Well about half the folks that watched this video got the completely wrong idea. They seem to think I am either promoting the use of mylar in sleep gear or that I am somehow teaching the use of it. I am not, I dont camp this way nor do I know the proper use of it in the manner. The idea of the video was to get comments from folks that use this material. No matter if it a failure or a success. No matter if you love it or hate it. I want to hear from y'all. I am also well aware of how its used in a super shelter, on a ground pad and under a hammock. No one can argue with using it in that manner because it does work for them uses.
David this is a great video and a learning experience for all for the channel to discuss. when making a super shelter Mylar is fantastic to reflect body heat and also reflect a fires heat. I just want to express my knowledge with the use of Mylar bags. people wear Mylar suits at the gym to sweat by reflection body heat back on the body. just for fun and a learning experience and also as a teaching aid try using a Mylar first with clothing and a fleece bag just for an hour in your yard. I know for me it would like a plastic bag full of water. thanks for all the fun and hard work you put into every video I enjoy your channel and every video.
Oh yes, its been a learning experience for us all. I had no idea they wore this stuff as clothes for a sweaty work out. Thanks for sharing that William!
David we are all in this together. hopefully viewers will come out of this discussion with knowledge to advance themselves in a just in case situation. I have used the SOL bivi survival bag while hinting in upstate New York in the winter and I was very warm but started sweating a little in 4 degrees. I took my hat off right away letting some heat thru my head. and wound up taking off my top layer they work well but you have to ventalate body heat some times. just for fun put 2 hand warmers at the bottom of a Mylar tube tent and stay inside wearing clothing and you will see what I mean.
At 902 comments at this time I just do not have time to go through the comments so maybe someone else made the following thoughts already. My lar does not stop conductive heat loss and so therefor you need to keep a space between your body and the mylar just like you said. Mylar reflects radiated heat but not conducted heat.If a person is in the cold and holds up a single layer of mylar close to your face just like you did, they will feel warmth. Now touch your face with the mylar and you will feel the cold. That will demonstrate the difference between radiated and conducted heat transfer. No my choice as to your options is.......none of them. In my opinion you left out the best option of all. First of all I would wear to bed nothing but a layer of polypropylene and nothing else. Next would be the mylar bag to block radiated heat from escaping and as a vapor barrier. Next would be a fleece bag. Next would be another fleece bag. And finally would be the final mylar bag to use as a windblock. I think that combo would excel all the other options. I would not worry too much about sweating inside the mylar vapor barrier inner bag. Yes it will feel clammy and not very comfortable due to the clammeyness. BUT you will be warm since the sweat cannot evaporate due to the vapor barrier. I of course am referring to my physiology. Others perhaps may just sweat way to much to even be able to use this type of sleep system. I have slept quite a few nights using a vapor barrier in my sleeping bag though it was not mylar and it really helps in terms of added warmth.
Fantastic comments Brother Lonnie! Out of 902 comment you are the only one that explained the difference between radiated and conducted heat. One other person explained the idea of how a vapor barrier works but you explained it better. I think your comment on that is good proof that if you understand this material it can be made to work. Thanks for watching Brother.
Lonnie gets it right, the human body can expel up to a liter or water vapor through breathing during the night in a 9 hour sleep session. Sleeping in freezing weather in a down sleeping bag is going to keep you warm until your breath condenses. If it warms up, that frozen breath vapor may then heat up and become a fluid again, soaking the surface that it condensed upon. If the vapor barrier liner is used, this helps mitigate the interior of the down sleeping bag from absorbing that water vapor. It is trapped inside the vapor barrier liner. Lots of ways to move the moisture vapor from your breath to the outer surface (in the case of a double layer tent) through the breathable inner tent fabric to the inner surface of the rain fly. A kerosene lamp lantern is my favorite, as a 3/4 inch wide wick is about 10-13 candle power. Helps keep the inside surfaces of the tent shelter (a small enclosed tent) from raining on you when it warms up in the morning and the winds pick up. One simply works through the physics and addresses the variables. Try not to knock that kerosene lantern over, carbon monoxide battery operated detectors offer a sense of safety, doh! :{ EDIT: For those who use down sleeping bags, EXPED has the Waterbloc down bags which use Pertex Endurance 1,000 mm of hydro-static head, and in the large 1400 series 51.9 ounces of down. I have one. The use of Western Mountaineering HotSac Vaper Barrier Liner is a must. I add to that with a polyester sleeping bag insert from Sea to Summit to place inside the VBL. The VBL is inserted into the sleeping bag and cinched up tight. Then the sleeping bag is cinched up tight around the neck so that the expelled breath is expelled outside of the bag. The long johns I use are some polyester camouflage bow hunting long pants and shirtsleeves of polyester as well. Unzipping the bag, I roll out within the VBL and then exit it outside of the sleeping bag.
Having watched this, and your home made bedding roll with mylar, I ordered and fitted a layer of mylar, topped off with fleece ,for the floor of my tent. Best thing I've done, feels like I've got under floor heating, absolutely great. Thanks for the information.
I just want to thank you for your enjoyable videos. One reason I like them so much is because I am disabled and my husband and I used to hike and camp very often after we finished our time in the army. Unfortunatly I'm unable to do any of that now, but watching you and other bushcrafters brings back such good memories and its almost like I'm there with you ( as crazy as that may sound) It also helps that you're from down south like me, and I feel right at home. When I was away in the army I still had Georgia on my mind, especially the mountains in the north. Anyway, sorry to take up so much time just to say thanks and keep up the good work. :-).
In my opinion/experience, there are no real use for Mylar in sleeping gear. That is most likely why people can't agree. Making a "Super-Shelter" is a different thing. For really cold climates, ventilation and circulation is key to staying worm. Not creating condensation is your sleeping bag is key as well. Mylar will surely create condensation is sleeping bag/system. I'm a cold climate guy so.. :)
I agree with Survival Russia 100%. I watched an interesting video by the famous Mors regarding sleep systems and mylar and he go into the science behind it all and the major point he got across was mylar is only inteded for short durations never for longer periods of time.
I can agree with SurvivalRussia , he's paid his dues in a much colder climate that most of us will ever experience , and does it on a daily basis , , so I would give his comments much credibility.
Hi Dave, very interesting video. Well, here are my thoughts: I talked to a paramedic about the milar blankets and this is what he told me. They were constructed to reflect as much heat as possible in a very short time for injured people who are in a shock. The body reacts to a shock with moving the blood to the body core away from the extremities. So keeping the extremities warm for the time the patient is transported to the hospital is very important. But if the timespan is longer, the paramedics make sure that the patients don't sweat, wich often happens under milar blankets. That's why paramedics use real blankets and milar is only for first responders. So basically the problem with milar is the vapor barrier. It is not built for long term use. Now to the "best option" imho: I think it is option "E". Two sleeping bags inside and the milar outside. Why? Because the milar serves as a waterproof surface and reflective device. It will also reflect the body heat that made it through the two layers of the sleeping bags. But it will also lead to condensation on the inside of the milar. The condensation then will be caught by the second sleeping bag which will keep the inner sleeping bag more dry. On my last overnighter I just threw a non breathable rainponcho over my sleeping bag, it was below freezing. And I woke up at night, touching the surface of my sleeping bag and it was wet from condensation. I removed the poncho and after half an hour my sleeping bag was dry. People often forget how much moisture the human body looses even when sleeping. Non breathable materials like plastic, rubberized nylon or milar will lead to condensation on the inside and this leads to problems. So if I had to choose one option, I'd go with "E" but using milar would be my last option anyway. Cheers, Marc
Scouting Free I believe they have a breathable mylar that can be purchased,more expensive yes.From what I am seeing and reading it's sounding more worth it.thank you
Hi, there are breathable milar-like emergency bivys like the SOL. They reflect bodyheat and are breathable, but they cost around 30-50 bucks. That's where I put my money on :-) Cheers, Marc
Scouting Free I live where it does get cold but never have gone out below about 0F and I take an appropriate, if heavy bag. So never used the mylar for that. However, insulation works by heating the air within it. If the temperature. It works best closer to a heat source. The mylar works by reflecting the radiant energy back. It needs radiant energy not the heat itself. So yes, B or E should be the better solution. As well, the mylar is silverised somewhat on both sides so if inside the insulator it will reflect the radiant energy away from the inside. And yes, the moisture buildup is really important and you nailed that. Superheaters work by heating that enclosed air, not the walls, but still need to breathe the moisture out.
i would go for option E also, i dont like these types of mylar,they are very easy riped apart and a lots of noise use it almost every winter, at least once,i lay it under my sleeping pad my body has an additional heat barrier is not lost in the ground, and it keeps longer in the sleeping pad i have a cheap one in the car as a back up,or for any emergency but also having a "real" mylar blanket,it is basicly a construction plastic sheet with a reflective side one,very sturdy it is more bulky to pack away,but much beter than these thin ones Steve
Mylar's greatest attribute function is as a radiant heat reflector. If it contacts skin it will function as a conductor ... heat flowing to equalibrium (away from your body). Fleece is a great product but when wet it will not function as well as wool. My best-guess for optimum emergency survival: fleece or wool against the body then Mylar wrapped outside. Mylar also gets great thumbs-up for use to signal (light reflection); water collection (as a basin); and possibly as predator distraction (the noise it makes when waved about). However, my best and most reliable heat source inside my cabin is my trusty wood stove. Thanks for the video, got a thumbs-up from me.
I like the idea of the mylar on the outside and the fleece on the inside. The fleece can work as a wick if you sweat, and the mylar acts as a waterproof bivy and also reflects heat back at you. Great ideas David.
I really admire your videos for the fact that you don't BS anyone and you tell it "like it is"! Nobody is the perfect expert and there are WAY too many different environments to be able to do that. All angles should be approached! Far too many wield themselves as the "Expert"....While you humble yourself as an enthusiast! You search for the best answer...not only for yourself but for everyone....Thank you!
Thanks Gregory! I'm glad you like the videos and the way I do things. We think alike. There honestly aren't many experts out there that can be dropped off with nothing and survive any where in the world. It takes a lifetime of knowledge to know all the plants, animals and terrain across the globe. Thanks for watching my friend!
A space blanket may have saved my life one night on a mountain when I was 13. Got hypothermia which progressed to mono afterwards, but who knows how bad it would have been without that mylar blanket wrapped around me and my buddy. From that point on I've always carried mylar when overnighting.
HYPOTHERMIA HAS NOTHING TO DO WITH MONO ,, MONO IS A VIRUS , YOU HAD OR CAUGHT THE VIRUS BEFORE YOU DEVELOPED MONO , IT CAN TAKE MONO 4 TO 7 WEEKS TO DEVELOPE. HYPOTHERMIA IS EXPOSURE TO COLD AND DOES NOT CAUSE A VIRUS NOR DOES IT PROGRESS TO ANY VIRUS . HYPOTHERMIA ONLY PROGRESS TO DEATH IF NOT TREATED.
For those who are new at using the "emergency" blankets/bags please do your research before getting into situations where you may need to use it. Thinking you have an "emergency" blanket can be a false sense of security.. I learned the hard way....Myself and 2 others spent one night out and it got below freezing (we didn't expect that) we used the "emergency sleeping bag" and needless to say we didn't get much sleep, we are thankful that there was plenty of dry wood around and we were able to keep a fire going all night, but had I known HOW to take advantage of using the mylar as reflection from the fire we would have stayed much warmer and actually got a few winks of sleep. Since then I have appreciated the You Tube videos that have shown how to use these types of blankets/bags..I will be prepared next time. Thank you!!
The thing about the mylar space blankets is: they were designed for short term use for a trip to the hospital. The long term use tends to have condensation issues which needs to be dealt with. These blankets were never designed to come in direct contact with your skin and some air space is required to work properly. I think of the blanket as a shelter liner ,only for survival applications, because the chances you have 2 sleeping bags with you is doubtful. The most effective air space distance is between 2 to 6 inches.
Reallybigmonkey1 Thanks for all the Videos O.D. Dave totally enjoy every one of them! You are officially my favorite channel and I have seen nearly all of your videos 3 times.
Option E variation: On cold nights I use a Coghlan Emergency Bag ($7 on Amazon, weighs 3oz) as a bivvy on the outside of my down sleeping bag. My down bag is comfortable down to about 40. The reflective mylar bivvy gives me AT LEAST 10 more degrees comfort. I have slept comfortably in the upper 20s using the mylar bivvy. Yes sometimes the bivvy is damp on the inside in the morning. It's never been a problem tho. I turn it inside out to pack the next morning and for use the next night. I have also slept this way cowboy style and it keeps the wind off you AND the rain! (I didn't expect it to rain so I didn't set up my tent, but the bivvy kept me bone dry.) This is a really simple solution. It adds only 3oz to my kit. So for $7 and 3oz carry weight my lightweight down bag becomes a 3+ season bag. I think two mylar bivvies outside the down bag would give you even more degrees of comfort but I haven't tried that. PS: I also put my sleeping pad inside the bivvy. This helps maintain warmth in my sleeping pad.
This is a great discussion! I did a little winter camping, what I found in researching was what winter climbers call a vbl or vapor barrier liner. Appeared to be nothing more than mylar clothes and a mylar sleeping bag. They wear these base layers to keep their perspiration from wetting their insulation layers. Most use lightweight down sub zero sleeping bags and its imperative to keep the down dry. Which is why they put the vbl next to their bodies. When getting out in the morning the quickly pull out the liner, get dressed in dry clothes, go outside and turn the liner inside out. Their perspiration instantly freezes. They just shake it off and its ready for the next use. So, if I were in a freezing environment, I think I would trust their way of using it, more or less to keep the insulation layers as dry as possible. Its very uncomfortable to be damp when sleeping, but better than freezing!
Mylar next to your skin is not only uncomfortable, but will almost definitely make you sweat. Coldest scenario would warrant fleece, mylar, fleece and mylar. That maximizes insulation and gives you a waterproof outer skin. My humble opinion. Thanks for all of the crawling in and out!
Love it. I have carried several mylar packs in my briefcase, several in my EDC in my car, and moving blankets with it in the car - with tarps and cord. But, in my days out hiking we got stuck and the 2 mylar packs saved us a night that may have been terrible. They work well in Emergencies.
Back in the days that I was a Scoutmaster, we regularly camped during the winter months in NC. One weekend before Christmas at Hanging Rock, the high temp for the day was 9 Degrees F. Slept comfortable by laying a plastic ground cloth, the mylar reflective sheet, a 3/4 length closed cell foam pad, my down sleeping bag (rated at 30), pulling the other half of the mylar sheet over the sleeping bag, and pulling my field jacket over that to weigh the mylar down after I had undressed and climbed in (could have used something else, or taped it, but this worked, and I was being lazy) all beneath a tarp set up as an open-ended A-frame between two trees with a paracord ridge line - unheated. I had learned years before that you NEVER get into you sleeping bag in the clothes you wore during the day - as they are damp with perspiration (even if they feel dry) and cause you to sleep cold. If you can manage it, wear fresh dry socks.
I recently used your idea for mylar. I left my 15' sleeping bag at home and took a 32' bag and an emergency sleeping bag. The temp has been unpredictable this year. If it got too cold I would have slipped my bag inside the EM bag, and I knew I would be warm. Turns out, ANOTHER one of your Brilliant ideas lighten my pack by 2 lbs. Dude that's A LOT! Thank you
I would use option B or E, because i would keep the insulation close to me, and the wind block and reflection as the outer layer. This would make the mylar work mostly as a wind stop, but also a heat reflector for all the insulation layers in the inside.
I would say B (or E if you had the option when it's really cold). I had a week of camping, continual rain, and water eventually leaked into my tent so I was forced to sleep in my car. My lightweight sleeping bag wasn't cutting it, so I used a reflective windscreen shade over the top... worked a treat!
Loved the video, loved the comments. Really something to think about and at the same time funny. One of the comments made me laugh till I had tears in my eyes. And you crawling in and out does show the strength of the material. That stuff looks really delicate. And you get in and out of them so well. Thanks for a really fun video.
Wow awesome! You thought of it all, and actually showed it all with them two types used together. I like option E the best to stay warm and not be affected by cold and sweat. I prefer the Mylar not close to my body. Keeping the sweating more at bay. Thanks for sharing your budget knowledge on the fleece bags & the reflective duct tape for strengthening the Mylar bag. Thanks or also showing how fast and easy it is to put in place & get in and out of the set ups too. Looking forward to your next video's as always!
I would stay home wrapped up in a woobe watching all of your older videos and not worry about mylar blankets ever. It is hurting my brain just thinking about it. LOL. But if I were going to actually go out there in the cold then I would think that one layer on the ground to prevent moisture rising into my body and then one layer in lean-to fashion over my body reflecting the fire that I would have started several hours prior to constructing the Sleep System. Tada
Quite honestly I don't know why these things don't come with instructions. I mean if they wrote it on mylar it wouldn't add that much weight to the package, would it? Maybe even some picture diagrams. Perhaps they can invent a type of space blanket that is made with thin iron ore and would magnetically become polarized against the iron ore in the soil and they could create a floating space blanket that would prevent ground convection and that. ...Hey that's a really good storyline. I think that will be the theme of my next novel.
Been a subscriber for a couple of years, luv your channel. I live in the western part of Virginia near the mountains. I’ve been experimenting for years with minimal kit. First in my back yard and then in the mountains. I use a SOL double sized Mylar heat sheet cause it’s bigger, quieter, and resists tears, and safety pinned it to a poncho liner. I reinforced the Mylar with a little clear packaging tape prior to pinning it. By having the insulation on the outside it reduces convection heat loss. I found it to be capable as a blanket or quilt with seasonal clothing to take me down into the 30s. I do not use it as a sleeping bag. It also makes a reflective tarp and under quilt for my hammock with elastic cord. Or if you put a really large zipper horizontally in the poncho liner so you can get your head through it and a horizontal slit in the Mylar reinforced with clear tape, offset by about 6” , it will hang a little lower or even in the back, into a more effective insulated poncho that will also keep you dry. It’s really great to use in natural shelters on a drum liner mattress or foam pad. When I have used a Mylar bivy I have always put a 2 inch hole in the bottom, so that some of the hot moist air can escape from the waist down, and with the large opening at the top, it creates an ok bellows effect when I turn in my sleep. You can also have the shinny side out to create shade, or if it is green Mylar you can reverse it before pining it and put it on the outside and the liner next to you for rain or snow. Of course both can be separated at anytime and used independently of each other in the Summer as tarp and blanket. It weighs ounces and is multipurpose. I am a French and Indian War, and Revolutionary War, re-enactor. I have used a wool blanket in some of the ways just mention, but this better, because it is warmer, drier, and dries fast if wet. Hope this info helps someone else.
John Davis made a great point about using non-absorbent materials in conjunction with Mylar augmentation to sleep systems. You've made a point of including a bug net/mosquito bar in your survival kit recommendations. That happens to be one of the very best things that can be used to enhance loft/dead air space within a sleep/survival shelter unit. In very cold weather, folding a large nylon mosquito net bar into an extra layer within your blankets or bag systems not only gives you the non-compressible netting material for air trapping, it also will NOT absorb moisture! As to my personal experience with Mylar augmentation, here in AZ, the winter air is exceptionally dry and I used a 32 degree bag with a silk liner inside a SOL reflective survival bivvy during a February Scouting Snow camp out. 7000 ft elevation, 0 degrees Fahrenheit. I had a Therma-Rest pad under me, but no further insulation beneath. It was still cold, but with layered clothing in addition to the bag and bivvy, I was just fine. Now the SOL bivvy is designed to be less Sweat inducing than straight Mylar, but it also has Velcro tabs along its edges and that allows you to adjust it for venting to reduce sweating. I would tend to agree with the idea of not putting Mylar directly near the skin, but rather outside the rest of the sleeping gear as a weather barrier. Your Fleece - Mylar - Fleece - Mylar option seems pretty solid as it places the layering in the position to repel wind & water from outside as well as close enuf (thru only 1 layer of Fleece) to reflect body heat. Either way, multiple layers that can be adjusted to ANY situation seems the best idea. More Fleece and less Mylar may make sense in warmer or wetter environments, but the point is, you have options if you were to use the 2 Fleece/2 Mylar to enable any of your demonstrated choices.
Fantastic comments and info Kelly! Yes, with four pieces of gear like mylar and fleece it can be tailored to any situation. I'm going to experiment with your netting idea
I did learn something from ur video & the comments. I never thought much about it . I just keep a one in the car for emergency & one in an emergency bag. Thanks. Im glad your working on more videos too.
Hi there my good friend. This is a great idea for a video. This issue have puzzled me too. I will follow the discussions here in the comments section. And one day I might test some of the upcoming ideas. Love your cats! Thank you for sharing this! /Ulrica
Hello Ulrica! I thought it was a good idea to put this all out there and get some discussions going. Its worked so far and lots of differing opinions. I figured the cats would steal the show a lot more than they did. LOL. Stay warm and thanks for watching my good friend!
I am not understanding where all this talk of sweating is coming from. I have "never" sweated under mylar. I want my body warm so I wrap up in it. I have never wanted my face hot or even warm so I leave me face out. No condensation.
I like c seems if it was cold windy,it would keep the noise down,but my knowledge of it is zero. great Video and love how many ways you used it..and yup i'm going now to find the knowledge others have shared Thank You..
for me option C because (and this is just my thoughts and what I have used in my hammock sleep set up in the past) I found when I used mylar blanket as a underblanket then the hammock then sleeping bag I had a damp patch on my back area in the hammock and sleeping bag the temperature was about 8 c. but the next night I swap things about and used a sinthetic underblanket then mylar laying in that then the hammock a fleece blanket to lay on a wool blanket over the top , that was warm and comfortable and dry. so what I'm saying is for me mylar has to be away from me enough that my body can breath. Atb jam.👍
I have used Mylar as an underquilt/windshield in colder hammock use. My experience, is that Mylar is conductive, and sucks heat out of you on direct contact. It reflects heat that is radiated though. So when I used it under my hammock, I hung it so that the mylar sagged deeper than the hammock did. That way there was air space between the hammock and the mylar. I have not tried this below freezing.
Reallybigmonkey1 thanks dave ,like you and many others it's just a matter of trying different ideas out and sharing with others. Then we all learn more. Atb jam.👍
VanishingNomad thanks mate that's sort of how I used it . Also find when I have my tarp up its lots warm if I put a mylar sheet under the ridge line pulled out against the tarp on the inside, the side the wind and rain is hitting . If you get what I mean.
Great video with alot of options, surprising how effevtive this really is, i use Mylar above my ground sheet, makes a huge difference. Thats a whole lot of work... going through those options ! Thanks !! I will experiment
Excellent video as a research experiment, respect on your patience Dave. I would agree on condensation issues, which can lead to cold, wet clothes & situation depending - Hypothermia.
Option E is the only one I could deal with.My best result with milar was to use it as a ridge line tent between the tarp an hammock,at 24deg. F. worked well with little condensation. Too many options! Thanks Dave. ZZ.
Man you sure know how to spark discussions. Excellent talent you have there. I read Lonnys comment on vapor barriers and started looking into them. Found a company named Warmlite. They had the best explanation I have seen about heat loss and cooling for all climate conditions. Well worth checking out. They have a full line of vapor blocking products. Some is quite expensive but the idea is there. Might be fodder for future video topics. Never know
Thank you my friend. Lonnie had a good explanation and a few others did but the discussions are usually "use specific" Like will it be in layers, or as a reflector or to wear against the body to protect your down bag. Lots of uses for this stuff.
2009+/- I basicly did option E on the AT at Bulls Gap. Wind was howling in mid october and cutting through our tent & there was snow on blood Mnt. 2 miles away. I wrapped mylar blanket around my big agnes sleeing bag. I stayed warm as the wind could not get through. In the morning my bag was wet on the outside. I stayed warm and dry. Dryed out bag in the morning and started up trail. My wife slept inside a construction garbage bag inside her big agnes sleeping bag she got damp but stayed warm. She dried out her long johns while hiking. Mylar saved my life as it was cold and probably kept bears away with all the noise. We jet boiled chili inside our tent that night as it was so windy no fire could have stayed lit.
This will sound like the Grinch,,, and I don't think of myself as a light sleeper,,, I used the mylar once over my sleeping bag. The noise, noise , noise,,, I could not stand the noise,, and I didn't get much sleep... I think I will try taping it to the inside of my rain fly... Thanks Dave,, and keep up the good work....
Some folks get freaked out over the noises of the night and the crinkling Sound might just cover them sounds up enough for them to get to sleep. Thanks for watching Brother!
I'd wake up every time I'd roll over due to the mylar noise... and I'd get claustrophobic from sleeping in a single sleeping bag. I take two sleeping bags and zip them together... then put a couple wool blankets on top... makes plenty of room to stretch out and take off a layer of wool blanket if I get too toasty. Mylar coated Reflectix is good under a sleeping pad... at least 4 feet wide and 6 feet long... cuz I roll around a lot at night sometimes and don't want the ground to get me cold. At least this way I defeat sweating and condensation build up from being incased in a plastic bag.
Willy Bee I fully agree; used a mylar blanket during E&E training but it is noisey as hell. If you are busy wit E&E it is not a good idea. You will also need a dump pouch to pack it away as you'll never going to get it folded away to the size it was before you opened it.
2 mylar seems a bit much.I'd worry about sweating too much. I'd rather have it on the outside but not taped up so I can adjust if needed. Good work Dave thanks for sharing.
You shoulda' said you all should take notes. LOL! I am gonna have to think on this one!!. One problem I foresee is the build up of moisture. I will get back to you. Good show, very thought provoking. Happy trails.
A is basically a reflective vapour barrier liner, often used in winter to keep the insulation dry, as you always sweat some over night and that humidity travels through the insulation and of your bag, freezing on the inside of the outer sleeping bag layer, which reduces insulation properties r night by night.
I took a winter outdoor class and was taught how you lose heat. RECC was the acronym. R is for radiation, like infrared cameras see; the Mylar will reflect it BUT once it warms up you will still lose the heat as it radiates as well. Mylar: no long term effect. E is for Evaporation. If you are damp/ sweaty and the moisture evaporates, you get colder. Like a swamp cooler, or sweating in hot weather. But if you have the Mylar against your clothes, the plastic bag keeps the moist air from leaving; Mylar works here. C is for Conduction. Don't touch the ground or cold things. Mylar has no effect on this. C is for convection. Moving air can carry heat away from you. Warm air rises, so if you let the air near your skin move away, you get colder. Mylar bag can help: traps the air. In winter, keeping your sleeping bag dry is key night after night. We all sweat. And in cold weather (like 20 F or below) the air is dry. Your skin sweats a tiny amount ("insensible perspiration") to keep itself moist. That moisture moves away from your skin, into the bag. But it will reach a spot where it is cold enough to condense into liquid and freeze. You will have ice inside the bag. So using the Mylar against your clothes inside the fleece will keep it dryer and warmer. Your clothes will get a bit damp, but getting out of the bag they will dry really fast. Above 20 degrees, I find liners like this much too hot. Below 20, small liners like these are great as part of my sock system inside my boots. Look up "VBL" or vapor barrier liner.
I've used both mylar space blankets and the 5x7 survival tarps (with mylar reflective side) on many trips. The thinner space blankets were very handy on unexpectedly cold mornings on trips in the Cascades. We used them like a wrap-around blanket and tried not to let too much moisture build up in our clothing. I've used the 5x7 survival tarps under my sleeping pad on nearly every backpack trip in the past 10 years and it really helps keep my body heat from being sucked into the ground. I'm intrigued by your options here! I think that option E, with two layers of fleece and an outer layer of mylar would be my choice. Great topic!
Option E. The mylar will keep the warm air in and the cold from passing any layer. It will also keep the wind out. Your sweat will be absorbed by the fleece and the fleece is better at insulating when close too the body. The problem with putting the mylar on the inside is that any heat that goes through and into the other layers wont be able to get back to your body.
Ok...Heres what ive done and can confess to. I made one of those storm shelters with the open front. Basically...the tarp on the ground and behind me with the sides. Kinda like a super shelter without the drop plastic on the front. Got in the mylar bag with my cloths on and tried to sleep. Could barely stay warm enough to even just lay there....never mind sleep. And the noise from the mylar and plastic tarp...I would have rather died. Even contact cemented mylar to a plastic tarp and when I used the same tarp in the summer...heat from the sun melted the glue and the mylar came off. Had one of those half moon pillows...the ones full of beads. I woke up from being in half sleep mode going mad because I thought a moose or fox was right beside me. It was because all the noise coming from the pillow. That was in my hammock. Now...if I were going to pick one of daves options it would be his forever sleeping system. I think mylar belongs in the car for emergincies while one is awake and wants to get warm.. Although something is better than nothing...mylar is just too dam noisy for me. So are plastic tarps for that matter. When it comes to this is what ya got...Ive had far better success rolling up in a blanket and getting inside a giant plastic bag. Not very noisy. Woke up feeling great because I was warm. I suppose id pick the bag...then mylar over that or make a bag from the plastic drop sheet. Id rather do that and be forced to roll up in the sleeping bags and not use them properly than sleep on mylar as a first choice. Just an opinion. Those military systems are great. Sleep right on cold ground without a problem. Mylar is good for making solar ovens as the lining inside...might be good for reflection like a mirror...dont know....never tried. My mirror works great. Mylar....yuk. hahahaha......If I fell through some ice I might want mylar...dont know though...never done that before. Its small enough to carry around though.
I must have missed this when it was posted. I wish I had some input to give but never used mylar in a sleep system. Thanks for taking the time to make the video, it was an interesting question. Take care Dave
Just one observation: The cold doesn't "get in" as such, it's always the heat that gets out. When you get cold it's because the heat is conducted away from the body. If you compare putting your hand on a piece of metal and a blanket which are both at room temperature, the metal will feel cooler - even though it's at the exact same temperature as the blanket, because it is a good conductor of heat and will quickly allow the heat from your hand to be conducted away rather than "allowing the cold in" to your hand, whereas the blanket, being a good insulator will not conduct the heat away from your hand so quickly. It's a bit pedantic to point it out, maybe, but it's physics 101! Cheers, Dave.
Nilguiri the word pedantic is defined as ostentatious and overly concerned with minute details. I find the word pedantic ostentatious as well since it is often used to impress others.
The cold will make it through. Mylar is great but it's not magical. Wind goes right through fleece, so I'd put the mylar on the outside no matter the configuration. All that would be toasty in most situations I think. But I think it's not good enough for the deadly temps you mention.
I agree with you, the Mylar will help keep the wind off you. Keeping the Mylar closer to you won't allow the isolating quality of the fleece to work and do it's stuff.
Really appreciate all the thought and explanation that goes into these videos, as well as the intention to build a knowledge base from the community. My own experience with mylar, as demo'd in this video is that sleeping in this bag can be really noisy, though warm. I use a single mylar sheet under my Wiggy's bag when in freezing weather, right on the floor of my tent with the Wiggy's on top, to sleep well. No crunch, crunch during the night. The extra $ for the Wiggy's is well worth it.
I've used it over my one man tent then I put one at the bottom of my tent my tent was a summer tent my bag was good to 40 I was camping in below 20 next to the river and stayed warm the only condition was on the outside did not get in the tent I don't know if that's the beat way but it worked out well for me
David, you always seam to give good information in your videos. You help others to learn the camping skills to have acquired thru out your years of experience. And, I am grateful for this shared knowledge. Thank you for your videos. From all I have read and been told about proper use of a space blanket, I would not use them in the manor you have illustrated for fear of getting hypothermia during the night. No matter what you want to call it, sweat or perspiration, all mammals continually loose body moisture every minute of their lives.24-7-365. An emergency blanket, sometimes referred to as a first aid blanket, space blanket, Mylar, thermal or weather blanket, is used in emergencies to reduce heat loss in a person's body caused by thermal radiation, water evaporation and convection. Cold air tries to carry your body heat away. Blankets form a barrier between your body and that cold air. Since heat doesn't transfer through the blankets very well, they keep the heat from getting out. The colder the surroundings are, the more insulation you need to keep your body heat from escaping too fast. A space blanket (also known as a Mylar blanket, first aid blanket, safety blanket, thermal blanket or weather blanket) is an especially low-weight, low-bulk blanket made of heat-reflective thin plastic sheeting. In my humble opinion, these are the only methods in which to use space blankets. Use the shiny space blanket between you and the ground to prevent heat loss. Lay your sleeping pad on top of the space blanket. Then, lay your sleep system on top of the pad. Finally, lay a second space blanket over the top of your sleep system if you are not going to have a fire. The space blankets work best with 4 to 6 inches of dead air space between you and the blanket. DO NOT use the blanket in a bag form for extended period as they will trap escaping body moisture and you will start to get hypothermia. When using a fire, setup the blanket on an angled wall (30 to 45 degree angle) behind you with the fir burning in front of you with a second blanket on the ground and your sleep system on top of it. The radiant heat from the fire will be reflected off the space blankets back to your body warming you up. Think of yourself ass a human burrito in a reflector oven. To minimize heat convection loss a good layer of dry lofty materials is best placed between the ground and the space blanket. I hope you and your family are doing well.
I can only relate my experience. As a long-distance ultralight thruhiker I have tried many things to keep me comfortable at night. My sleep system as it is is good to 10 degrees. I have been on hikes where that wasn't enough, whether because of rain,snow or wind. I always have a mylar blanket with me. As a gram weenie I evaluate everything that I carry and it is always going to make the cut. I've tried it in many configurations and settled on wrapping it around my airpad and laying on top of it in my bag. Everything other way I have tried produces condensation. Being on trail for weeks and months at a time my biggest threat is always going to be moisture. If not a direct threat to hypothermia then I have to stop and dry my gear or carry it uselessly wet on my back. Great vid!!!
I'd only ever use one in an emergency situation to block wind and trap heat. I have a grabber that I use as a ground cloth in the winter and have noticed no difference using it face up (reflective) or face down (conductive). Option E is your best bet to block wind, trap body heat and conduct heat towards you. My advice is carry a better system, learn how to build a shelter and use fire to your advantage. There is no sense in trying to patch something together when there are warmer and more efficient options these days.
Ben you are lol over you tube from living survival camping with Chris and will from prepared mind 101 and mantas outdoors. David Did aka a point of using 6 different methods of using the Mylar tube tent as a sleep system. My concern I that someone my use this system in the wrong way example is maybe a boy scout or a first time camper going out into the woods thinking they are doing something right turn very wrong. Most people get hypothermia in wether between 40 and 50 degree Fahrenheit. I believe David's intent was to help keep people warm with different options and no intent to cause anyone to get in further problems in the wood camping. We are lol in this together and let's have fun next lol be safe.
with all respect , William , your comments supporting the SOL Bivy Bag down to below 0 F and sweating is somewhat questionable at best , , and a downright a great stretch of the truth at its worst. . I won't directly challenge you for now , , but I have a SOL Bivy ... I've not had to use it yet , but when I ever do , I'll let you know how it comes out. In the meantime , I don't hide behind a mask , , so I ask ' why do you ? '
lol I'm not hiding behind a mask my kid did that for me years ago so I left it. I am a 52 year old man with about 200 camping trips under my belt of experience from around the world. When Mylar blankets first came out they were sold as emergency space blankets that were used by NASA for pilots and astronauts. The time I hunting it was almost zero degrees I was not car hunting I was 3 hours walking up a mountain on state land. It was windy and it was cold so you are warm and cold when you stop for a minute or two. If you ever opened your sol bivvy you will see it is breathable it is not marked waterproof but I have used it in rain and had my feet out side my tarp I was not wet. but still you will sweat so if you use it friend you may have to take your jacket off but it is a good wind blocker
Hi Dave !! Another great video that is sure to get the discussions going. The comments I have read have been very informative and thought provoking. I like the single or double bags with the mylar on the outside. I think we need some really cold weather so the testing can begin !! Thanks for a really good video. My family loves you cats !!!!
Thanks Ellis, I'm glad you liked it. Well some comments are good, some bad. Some folks are even attacking me because they think Im trying to teach how to use mylar. I dont know, thats why Im asking! LOL. Who can go wrong with cats? Thanks for watching
the advantafe here is lighness and being prepared for an unexpected cold situation while traveling. once i went to visit boston in july and took a train to rockport at the end of the day. the train stopped at Rockport and i had to exit the train at midnight. walking towards the town a policr car pulled up and the officer asked me where i was headed. i told him to get a room. he said you best head back a the rooms are taken. thus began the worst night of my life. il take one mylar and a liner please. and one a them cats.
After 5 years, I still do not know the best answer! But this discussion is interesting and useful, and the most important result is to teach people to understand the layers'concept and the reflective / insulating / water-resistance / wind-breaking / moisture-wicking properties of the different materials, and allow one to take the best decision based on location, temperature, wind, rain, humidity, sex, body mass, methabolism (people with hipothyroidism have very little resistance to cold), what you eat at night, the kind of protection you have with you, how mobile you have to be or how long are you going to stay in the same place... Thanks, good luck to all, praise may be the Lord as His birth is to be commemorated tomorrow, and may His peace be with everyone!
1) *You ALWAYS "sweat"* -- otherwise, you're dead. Mylar on the inside will prevent that sweat from hitting your insulation. 2) *mylar fleece fleece mylar* -- reflective, convective convective, and then the second mylar: MORE convective (anti-breeze). The two layers of fleece provide the majority of your convection-slowing insulation, but you still have all that open weave ventilating hard-won heat to the sky. Hence, the second mylar on the outside -- not as reflective protection, but this time as wind-stopper.
Another good one again Dave, information is knowledge,and knowledge is wisdom. Loved the Cats in the background, my Cat is sleeping next to me,i can feel the heat from her!!!
Every time I've tried to use mylar I've ended up damp. I think I would go with fresh, dry clothes and option B. If that wasn't enough I'd go to E. My thinking is that the mylar on the outside would also act as a wind and water resistant shell. Either way I'd expect to wake up wet.
Per usual, David, you produce a very watchable and enjoyable video. I like your work on variations. Here's my input on Mylar: First, and I share this because I have been corrected on it, Mylar itself is just the polyester plastic. It is the substrate for the the aluminum, which is the really effective "ingredient". I call the whole Mylar and aluminum product "Mylar". I think we all do. Mylar will insulate you no matter whether it is next to you or separated from you by other materials. It's sole purpose is to block convection and reflect infrared. It is absolute crap for conductive insulation. I think most people know that last part. In most situations it is best to have the Mylar on the outside to create a windbreak. The two exceptions to that occur for specific reasons: 1. If it is an emergency and you are trying to warm a person up, then it is best to get the Mylar as close to the body as possible(faster heating) so that the infrared is being reflected onto your skin rather than onto your insulation(slower). Once your subject is warm it is best to have a layer between them and the Mylar to reduce the eventual moisture build up. 2. If you want to protect the Mylar from damage, then you have another material between it and the outside world. The thing is that every permutation you show us will work, but will be varying in effectiveness, based upon the elements and purpose. If I was tasking myself to create some sort of bivy with the Mylar(that will last), then I would have a fleece/wool layer on the inside, Mylar on top of that, then some sort of durable material (wool or synthetic) on the outside. One thing people seem to forget is that Mylar is noisy. If it can be sandwiched between materials it will be muffled and more tolerable as you try to sleep....or stay hidden.
The noise that mylar makes would drive me absolutely crazy if I was trying to sleep. I agree with Survival Russia. You are better off with a material that will breathe and allow condensation to escape.
Dave you surely got your daily workout crawling in and out of those things. Personally I would go for Option E simply from the standpoint that the mylar looks like a bear to crawl into and keep from bunching up. Thanks for your hard work and take care brother.
My first introduction to this product was after the marathon in New Providence, RI many moons ago where those of us near death were given a "blanket" and pointed in the direction of the medical tent. It did a fair job keeping my heat in as I moved but I would have preferred a sweatshirt. Every time you moved the cold air would blow in and remove the heat you were trying to gather. Once I was stationary on a cot it did a much better job and I was able to recoup relatively quickly. I learned three very important lessons that day; 1) Don't run your second marathon 6 weeks after your 1st... 2) Don't run your BEST EVER 20 miler in a race that covers 26.2 miles! and, 3) "THE WALL" is not something you can see but it is definitely a physical reality and will cause you to slow down to a crawl when you hit it. I actually didn't learn much about mylar blankets but I would suggest they would be good to keep on hand for any emergency where a patient needs to be kept warm and can be kept still. : )
Hi David. In your usual form, a great video. THANK YOU. I choose option E. It's probably advantageous to have the Mylar away from the skin and the fleece near the skin for wicking. Best wishes!
I have no experience with Mylar really, but my opinion is, with option A, with the Mylar inside, if you were to sweat, it could pool up, at lease with the fleece first, there is something to absorb moisture. though if you're warm enough to sweat, you won't be cold, but its not very comfortable to sleep in a pool of sweat. lol Depending on the situation, having fleece on the outside, would allow for the outer layer to get wet, and freeze.
milar as an elcheapo floor mat between ground and your self infl sleep mat. As you said, the ground sucks the heat out. As we use it for camping and not for emergencies. You also dont need to worry about it ripping so much either. They are as cheap as a packet of sweeties, way nothing and you can have 3 of them easily at hand. Scottish winters have been mild past 4 years and milar has been in my pack everytime. I am a lizard that needs to heat up on a hot rock of a day, so trust me when I say these are efficient. Thanks for the video Dave, glad to see you have shaken off the flu.
What i know about heating and insulation, your best bet would have been option H. That would be mylar, fleece, fleece. mylar. or in heating and insulation terms vapor barrier, doouble layer insulation, vapor barrier. Love your channel. watch you all the time.
So.. Option "C". It what I have used for years in my "two wool blanket" set up. I know people balk at the "weight" of wool - but two wool blankets with Mylar in-between... well you "could" sleep out under the stars in rain with that...
I got a wool (80%) blanket recently and I could not believe the weight. But I love the durability, antimicrobial properties, its crazy ability to keep you cool or warm, and to wick moisture away. I used wool for cloth diapering and as long as my covers were well lanolized all i had to do was air them out and they could go on like that for a long time. Nothing else can do that!
Journal Of A Wimpy Prepper-Question #1: Is the main purpose you lanolize for less water weight from absorption? Q.#2: Does lanolized wool create more of a fatwood effect than non-lanolized? We thank you for your suppor, er, response.
I personally like to use my tarp shelter with the inside lines with a Mylar blanket of some type and then have a 1/2 circle Mylar wall some where around 3 ft. tall which reflects most all your heat into your Mylar lined shelter and I sleep in various configurations of the USGI 4 part sleep system with a sleep mat. I've used this setup on many occasions in very cold weather and always stay comfortable. By the way Dave, I love all your ideas and videos...keep'em comin! Maybe someday we'll meet and do a cold weather camp out!
Brother I love hearing from real world experiences with this stuff! Maybe Ill see ya in the woods one day. Thanks for the input and thanks for watching.
Great video! We have missed you! I am amazed at how easily you could crawl, wiggle, slide, slither, squirm, wriggle, twist, whatever you call it :-) in and out of those Mylar blankets! You were doing some serious Monkeying around for sure! I probably would have needed Nick to place his foot at the top of my head and push me in. LOL Like I said, interesting video and great information. Thank you so much for uploading it. :-)
Thanks Lyn, I'm glad you liked it. LOL, all that wiggling and twisting keeps me young. Check out some of the comments on here, they are pretty educational. Thanks for watching and may God bless you.
i would use two fleece bags together and put mylar on outside.but also put holes in mylar to let moisture and humidity out.no matter what you do you will get moisture.anyone who has ever slept in a tent sealed up or a vehicle with the windows up in the winter knows you will get moisture.the mylar works by reflection so putting holes in it will allow some moisture to escape but cut down on amount of heat reflected.i personally would only use mylar on top or side of tent or shelter.not on my body.keep the vids coming bud.love your work
well during our training we were told to just wrap the blackest loose around us and sit ! now IV only had a chance to use it 3 times it was warm but it was wool mylar wool 1st time 2nd time it was just mylar 3 Rd time was I use it as a ground cover 1st time warm 22 deg. no fire toasty 2nd time28 deg not to bad warm but not hot 3 Rd time sucked don't lay directly on it has no heat value 35 deg btw but what you done there is made a sleep system bag mylar bag should be good to 25 or so and bag on top should give another 10 deg now sweating is an issue but with clothes on your right I believe it would keep the sweat warm water is also a insulater if kept warm but given the fact that we were trained to make it loose to make a cocoon around you of warm dead air bag mylar bag should work great hope that helps say hey to Nick for me stay safe brother
but mylar supposed to be as close to your.body to reflect heat so the heat lost through the fleece would circulate back into the fleece and then to you at what temperature ? not sure depends on how much heat you give off then there would be the condensation between the layers as you said keeping the moisture warm I think you'd still get thin layer of frost on the mylar just be cause the air coldness on the top of the mylar but open top bag LEAVE ALOT of air out so maybe there won't be as much condensation anywhere
+kabaruser When people read it, it's not easy to understand if you don't use periods you have to slow down and study the context to determine where one thought ends and the next begins besides that it also shows laziness and is contributing to the stupidity of society. Is it really that hard? because trying to read and comprehend sentences without them actually IS hard. Is it a lack of respect for others?
Your video got me thinking. I got out my cheap Coleman fleece sleeping bag liner laid it out on the floor.Then I secured Mylar to it with carpet tape. Two strips about 2" long at the bottom, four strips along the zippered side spaced evenly apart and two strips across the top of the liner. I didn't bother securing along the forth side. I would have preferred to use Velcro for the strips but didn't have any and don't know how to sow (yet). That would help when it comes time to wash. I'm going to tryout this method with a Mylar between me and a cheap sleeping pad. Also, I like the two Costco Black Diamond Quilts I bought recently . I may be adding a Mylar sheet on top of the sleeping quilts. Thanks Bro, the video.
Sounds great! Nothing beats experimenting yourself and seeing how it works for you. We all sleep different in differing conditions so you may just find something that works. Thanks for watching
hey dave , i have made a over quilt with mylar sewed between two layers of cloth . it works great for bouncing heat back on me.. you can bye this mylar at joanns fabric by the yard, and it has nylon insulation attached to both sides of the mylar.. if you can't find it , i will send you some for testing .. ..bill
Thanks for opening this very interesting discussion Dave, it may just be a very useful reminder to us outdoors types , that we need to be better prepared than we often are, (I am guilty of this too!) my down sleeping bag packs up small, it's lightweight and I don't use it enough. I will remedy that. Thank you Dave.
I'm a old farmer, wool retains heat when wet, why fisher men, farmers , etc use to use it. Itchy yes, warm yes, option B with wool yes, insulation between you and the ground yes yes yes, but what do I know...I survived farming lol
Hi i have no heat in the rental trailor. The heater i bought broke an the heated blanket broke the electric stove was little help, but 2.70 mylar blanket i bought at Walmart really helped to keep me warm durning the wintet storm we just went through so glad i boughr them. First its a twin fleece blanket then the mylar on top of that then 2 more twin blanket on top an BAM!!!! Happy Happy Happy. So warm an cozy.
everybody mylar does not reflect heat, it reflects light, which can heat you if it's trapped in the bag. I keep seeing comments of it reflecting heat away from you, NOT POSSIBLE... it honestly works best with mild airflow so that you don't get soaked in your condensation, if not possible, put it close to your skin so that you get wet and not your insulating blankets... the tent configuration works very well and probably the best depending on the door... i have one with a mesh door and Ive slept in it many times ice fishing down to minus 20 Celsius... i just take off my shell layer and roll up in a moving blanket ontop of cheap sleeping mat
Iam1uglyguy it can help trap heat but can't reflect it... heat is just the energy that a material has through vibration... which can be lost by passing the vibration to other materials, emitting light, or chemical change
The heat that radiates from your body is infrared heat...and infrared is a designated descrption for part of the electromagnetic spectrum. It is a form of light, but at such a low wavelength, our eyes cannot detect it. Our skin, however, can detect it through the way it warms our flesh. That's why in infrared (thermal) imaging, your body glows brightest on those video screens where the bodypart is hottest, or where the metal is hottest on an object that's been held in the hand long enough to stop being cool. Heat and light in this case are considered to be essentially the same thing when it comes to the mylar's reflective capabilities. It IS reflecting heat. It's the same thing, and is capable of being simultaneously the same thing. It is both infrared radiation in the electromagnetic spectrum (light), and infrared radiation (thermal energy, heat).
ladyofthemasque they are not the same, and no scientists considers them the same, heat is the energy a material contains through vibration... No mirror in the world reflects heat... All light frequencies are the electromagnetic spectrum, infrared is just a portion, ultraviolet is another portion, visible spectrum another portion
okay here's my two cents. the video was educational you had some really good ideas. I myself will probably never camp like this but in an emergency situation it is good to know. you inspired me to get off the couch and start going outside. even if it's just in the backyard practicing how to start a fire with a bow-drill... I love all of your videos thank you for all your hard work and time you put into them.
Well about half the folks that watched this video got the completely wrong idea. They seem to think I am either promoting the use of mylar in sleep gear or that I am somehow teaching the use of it. I am not, I dont camp this way nor do I know the proper use of it in the manner. The idea of the video was to get comments from folks that use this material. No matter if it a failure or a success. No matter if you love it or hate it. I want to hear from y'all. I am also well aware of how its used in a super shelter, on a ground pad and under a hammock. No one can argue with using it in that manner because it does work for them uses.
Sorry Dave I am one of the folks that got the wrong idea. It is a good teaching video. It my have been unattended but teaching none the less.
David this is a great video and a learning experience for all for the channel to discuss. when making a super shelter Mylar is fantastic to reflect body heat and also reflect a fires heat. I just want to express my knowledge with the use of Mylar bags. people wear Mylar suits at the gym to sweat by reflection body heat back on the body. just for fun and a learning experience and also as a teaching aid try using a Mylar first with clothing and a fleece bag just for an hour in your yard. I know for me it would like a plastic bag full of water. thanks for all the fun and hard work you put into every video I enjoy your channel and every video.
Thanks Bro. Yes its intentions was to teach us all, including me.
Oh yes, its been a learning experience for us all. I had no idea they wore this stuff as clothes for a sweaty work out. Thanks for sharing that William!
David we are all in this together. hopefully viewers will come out of this discussion with knowledge to advance themselves in a just in case situation. I have used the SOL bivi survival bag while hinting in upstate New York in the winter and I was very warm but started sweating a little in 4 degrees. I took my hat off right away letting some heat thru my head. and wound up taking off my top layer they work well but you have to ventalate body heat some times. just for fun put 2 hand warmers at the bottom of a Mylar tube tent and stay inside wearing clothing and you will see what I mean.
At 902 comments at this time I just do not have time to go through the comments so maybe someone else made the following thoughts already. My lar does not stop conductive heat loss and so therefor you need to keep a space between your body and the mylar just like you said. Mylar reflects radiated heat but not conducted heat.If a person is in the cold and holds up a single layer of mylar close to your face just like you did, they will feel warmth. Now touch your face with the mylar and you will feel the cold. That will demonstrate the difference between radiated and conducted heat transfer. No my choice as to your options is.......none of them. In my opinion you left out the best option of all. First of all I would wear to bed nothing but a layer of polypropylene and nothing else. Next would be the mylar bag to block radiated heat from escaping and as a vapor barrier. Next would be a fleece bag. Next would be another fleece bag. And finally would be the final mylar bag to use as a windblock. I think that combo would excel all the other options. I would not worry too much about sweating inside the mylar vapor barrier inner bag. Yes it will feel clammy and not very comfortable due to the clammeyness. BUT you will be warm since the sweat cannot evaporate due to the vapor barrier. I of course am referring to my physiology. Others perhaps may just sweat way to much to even be able to use this type of sleep system. I have slept quite a few nights using a vapor barrier in my sleeping bag though it was not mylar and it really helps in terms of added warmth.
Fantastic comments Brother Lonnie! Out of 902 comment you are the only one that explained the difference between radiated and conducted heat. One other person explained the idea of how a vapor barrier works but you explained it better. I think your comment on that is good proof that if you understand this material it can be made to work. Thanks for watching Brother.
Lonnie gets it right, the human body can expel up to a liter or water vapor through breathing during the night in a 9 hour sleep session. Sleeping in freezing weather in a down sleeping bag is going to keep you warm until your breath condenses. If it warms up, that frozen breath vapor may then heat up and become a fluid again, soaking the surface that it condensed upon. If the vapor barrier liner is used, this helps mitigate the interior of the down sleeping bag from absorbing that water vapor. It is trapped inside the vapor barrier liner. Lots of ways to move the moisture vapor from your breath to the outer surface (in the case of a double layer tent) through the breathable inner tent fabric to the inner surface of the rain fly. A kerosene lamp lantern is my favorite, as a 3/4 inch wide wick is about 10-13 candle power. Helps keep the inside surfaces of the tent shelter (a small enclosed tent) from raining on you when it warms up in the morning and the winds pick up. One simply works through the physics and addresses the variables. Try not to knock that kerosene lantern over, carbon monoxide battery operated detectors offer a sense of safety, doh! :{
EDIT: For those who use down sleeping bags, EXPED has the Waterbloc down bags which use Pertex Endurance 1,000 mm of hydro-static head, and in the large 1400 series 51.9 ounces of down. I have one. The use of Western Mountaineering HotSac Vaper Barrier Liner is a must. I add to that with a polyester sleeping bag insert from Sea to Summit to place inside the VBL. The VBL is inserted into the sleeping bag and cinched up tight. Then the sleeping bag is cinched up tight around the neck so that the expelled breath is expelled outside of the bag. The long johns I use are some polyester camouflage bow hunting long pants and shirtsleeves of polyester as well. Unzipping the bag, I roll out within the VBL and then exit it outside of the sleeping bag.
Lonnie, what if you have to get up to pee and your completely naked on a very cold night??? LOL!!
rockfish007 bottle's are your solution
lonnie, can you recommend a specific type of fleece bag?
Having watched this, and your home made bedding roll with mylar, I ordered and fitted a layer of mylar, topped off with fleece ,for the floor of my tent.
Best thing I've done, feels like I've got under floor heating, absolutely great.
Thanks for the information.
That's fantastic to hear Neil!
I just want to thank you for your enjoyable videos. One reason I like them so much is because I am disabled and my husband and I used to hike and camp very often after we finished our time in the army. Unfortunatly I'm unable to do any of that now, but watching you and other bushcrafters brings back such good memories and its almost like I'm there with you ( as crazy as that may sound)
It also helps that you're from down south like me, and I feel right at home. When I was away in the army I still had Georgia on my mind, especially the mountains in the north.
Anyway, sorry to take up so much time just to say thanks and keep up the good work. :-).
Thanks for the comments and Im sorry you cant get out much more. Im very happy I can bring a taste of the Georgia mountains to ya!
In my opinion/experience, there are no real use for Mylar in sleeping gear. That is most likely why people can't agree. Making a "Super-Shelter" is a different thing. For really cold climates, ventilation and circulation is key to staying worm. Not creating condensation is your sleeping bag is key as well. Mylar will surely create condensation is sleeping bag/system. I'm a cold climate guy so.. :)
Thanks for the input Brother. I know you know a lot about cold weather gear!
I agree with Survival Russia 100%. I watched an interesting video by the famous Mors regarding sleep systems and mylar and he go into the science behind it all and the major point he got across was mylar is only inteded for short durations never for longer periods of time.
I can agree with SurvivalRussia , he's paid his dues in a much colder climate that most of us will ever experience , and does it on a daily basis , , so I would give his comments much credibility.
Thank you Billy :) I will soon present a new awesome sleep system I just got.
Thank you too Dave! :)
Hi Dave, very interesting video. Well, here are my thoughts: I talked to a paramedic about the milar blankets and this is what he told me. They were constructed to reflect as much heat as possible in a very short time for injured people who are in a shock. The body reacts to a shock with moving the blood to the body core away from the extremities. So keeping the extremities warm for the time the patient is transported to the hospital is very important. But if the timespan is longer, the paramedics make sure that the patients don't sweat, wich often happens under milar blankets. That's why paramedics use real blankets and milar is only for first responders. So basically the problem with milar is the vapor barrier. It is not built for long term use.
Now to the "best option" imho: I think it is option "E". Two sleeping bags inside and the milar outside. Why? Because the milar serves as a waterproof surface and reflective device. It will also reflect the body heat that made it through the two layers of the sleeping bags. But it will also lead to condensation on the inside of the milar. The condensation then will be caught by the second sleeping bag which will keep the inner sleeping bag more dry.
On my last overnighter I just threw a non breathable rainponcho over my sleeping bag, it was below freezing. And I woke up at night, touching the surface of my sleeping bag and it was wet from condensation. I removed the poncho and after half an hour my sleeping bag was dry. People often forget how much moisture the human body looses even when sleeping. Non breathable materials like plastic, rubberized nylon or milar will lead to condensation on the inside and this leads to problems.
So if I had to choose one option, I'd go with "E" but using milar would be my last option anyway. Cheers, Marc
Scouting Free I believe they have a breathable mylar that can be purchased,more expensive yes.From what I am seeing and reading it's sounding more worth it.thank you
Outdoors Idaho aww
Hi, there are breathable milar-like emergency bivys like the SOL. They reflect bodyheat and are breathable, but they cost around 30-50 bucks. That's where I put my money on :-) Cheers, Marc
Scouting Free I live where it does get cold but never have gone out below about 0F and I take an appropriate, if heavy bag. So never used the mylar for that. However, insulation works by heating the air within it. If the temperature. It works best closer to a heat source. The mylar works by reflecting the radiant energy back. It needs radiant energy not the heat itself. So yes, B or E should be the better solution. As well, the mylar is silverised somewhat on both sides so if inside the insulator it will reflect the radiant energy away from the inside. And yes, the moisture buildup is really important and you nailed that. Superheaters work by heating that enclosed air, not the walls, but still need to breathe the moisture out.
i would go for option E also,
i dont like these types of mylar,they are very easy riped apart
and a lots of noise
use it almost every winter, at least once,i lay it under my sleeping pad
my body has an additional heat barrier is not lost in the ground,
and it keeps longer in the sleeping pad
i have a cheap one in the car as a back up,or for any emergency
but also having a "real" mylar blanket,it is basicly a construction plastic sheet with a reflective side one,very sturdy
it is more bulky to pack away,but much beter than these thin ones
Steve
I always appreciate you doing these type of videos that aren't always the "traditional" topics. Keep up the excellent work!
Thanks Tim! I try my best to film stuff that no one else is doing. Keeps it different.
Mylar's greatest attribute function is as a radiant heat reflector. If it contacts skin it will function as a conductor ... heat flowing to equalibrium (away from your body). Fleece is a great product but when wet it will not function as well as wool. My best-guess for optimum emergency survival: fleece or wool against the body then Mylar wrapped outside. Mylar also gets great thumbs-up for use to signal (light reflection); water collection (as a basin); and possibly as predator distraction (the noise it makes when waved about). However, my best and most reliable heat source inside my cabin is my trusty wood stove. Thanks for the video, got a thumbs-up from me.
Thanks for the input Mike and I'm glad you liked the video brother
I like the idea of the mylar on the outside and the fleece on the inside. The fleece can work as a wick if you sweat, and the mylar acts as a waterproof bivy and also reflects heat back at you. Great ideas David.
I really admire your videos for the fact that you don't BS anyone and you tell it "like it is"! Nobody is the perfect expert and there are WAY too many different environments to be able to do that. All angles should be approached! Far too many wield themselves as the "Expert"....While you humble yourself as an enthusiast! You search for the best answer...not only for yourself but for everyone....Thank you!
in other words...thanks, bro!
Thanks Gregory! I'm glad you like the videos and the way I do things. We think alike. There honestly aren't many experts out there that can be dropped off with nothing and survive any where in the world. It takes a lifetime of knowledge to know all the plants, animals and terrain across the globe. Thanks for watching my friend!
A space blanket may have saved my life one night on a mountain when I was 13. Got hypothermia which progressed to mono afterwards, but who knows how bad it would have been without that mylar blanket wrapped around me and my buddy. From that point on I've always carried mylar when overnighting.
Thats some good real life experience. Thanks for the input and thanks for watching.
HYPOTHERMIA HAS NOTHING TO DO WITH MONO ,, MONO IS A VIRUS , YOU HAD OR CAUGHT THE VIRUS BEFORE YOU DEVELOPED MONO , IT CAN TAKE MONO 4 TO 7 WEEKS TO DEVELOPE. HYPOTHERMIA IS EXPOSURE TO COLD AND DOES NOT CAUSE A VIRUS NOR DOES IT PROGRESS TO ANY VIRUS . HYPOTHERMIA ONLY PROGRESS TO DEATH IF NOT TREATED.
For those who are new at using the "emergency" blankets/bags please do your research before getting into situations where you may need to use it. Thinking you have an "emergency" blanket can be a false sense of security..
I learned the hard way....Myself and 2 others spent one night out and it got below freezing (we didn't expect that) we used the "emergency sleeping bag" and needless to say we didn't get much sleep, we are thankful that there was plenty of dry wood around and we were able to keep a fire going all night, but had I known HOW to take advantage of using the mylar as reflection from the fire we would have stayed much warmer and actually got a few winks of sleep.
Since then I have appreciated the You Tube videos that have shown how to use these types of blankets/bags..I will be prepared next time. Thank you!!
Ya live and ya learn! Thanks for sharing that.
The thing about the mylar space blankets is: they were designed for short term use for a trip to the hospital. The long term use tends to have condensation issues which needs to be dealt with. These blankets were never designed to come in direct contact with your skin and some air space is required to work properly. I think of the blanket as a shelter liner ,only for survival applications, because the chances you have 2 sleeping bags with you is doubtful. The most effective air space distance is between 2 to 6 inches.
MrCelticatheart spot on mate!
Couldn't agree more!👍
Thanks for the comments.
Reallybigmonkey1 Thanks for all the Videos O.D. Dave totally enjoy every one of them! You are officially my favorite channel and I have seen nearly all of your videos 3 times.
MrCelticatheart m
Experience is the best teacher always. I like option C for the coldest weather.
How true Gary
Option E variation: On cold nights I use a Coghlan Emergency Bag ($7 on Amazon, weighs 3oz) as a bivvy on the outside of my down sleeping bag. My down bag is comfortable down to about 40. The reflective mylar bivvy gives me AT LEAST 10 more degrees comfort. I have slept comfortably in the upper 20s using the mylar bivvy. Yes sometimes the bivvy is damp on the inside in the morning. It's never been a problem tho. I turn it inside out to pack the next morning and for use the next night. I have also slept this way cowboy style and it keeps the wind off you AND the rain! (I didn't expect it to rain so I didn't set up my tent, but the bivvy kept me bone dry.) This is a really simple solution. It adds only 3oz to my kit. So for $7 and 3oz carry weight my lightweight down bag becomes a 3+ season bag. I think two mylar bivvies outside the down bag would give you even more degrees of comfort but I haven't tried that. PS: I also put my sleeping pad inside the bivvy. This helps maintain warmth in my sleeping pad.
Thank you for the comments! This is another fantastic example of how well this material compliments a down bag. Thanks for watching
Thanks David. I really don't know anything regarding Mylar and appreciate your ideas and many of the comments given. Thanks to all of you.
This is a great discussion! I did a little winter camping, what I found in researching was what winter climbers call a vbl or vapor barrier liner. Appeared to be nothing more than mylar clothes and a mylar sleeping bag. They wear these base layers to keep their perspiration from wetting their insulation layers. Most use lightweight down sub zero sleeping bags and its imperative to keep the down dry. Which is why they put the vbl next to their bodies. When getting out in the morning the quickly pull out the liner, get dressed in dry clothes, go outside and turn the liner inside out. Their perspiration instantly freezes. They just shake it off and its ready for the next use. So, if I were in a freezing environment, I think I would trust their way of using it, more or less to keep the insulation layers as dry as possible. Its very uncomfortable to be damp when sleeping, but better than freezing!
That's the best explanation yet Dave!
What a riddle, man!my two opciones are:B for mod.cold temp.,and E for high cole temp.nice stuff,thanks for teachin and sharing!Best regards,Paco
Sounds good Paco!
Mylar next to your skin is not only uncomfortable, but will almost definitely make you sweat. Coldest scenario would warrant fleece, mylar, fleece and mylar. That maximizes insulation and gives you a waterproof outer skin. My humble opinion. Thanks for all of the crawling in and out!
Thanks for the input and thanks for watching. I actually enjoyed all the crawling in and out. lol.
Love it. I have carried several mylar packs in my briefcase, several in my EDC in my car, and moving blankets with it in the car - with tarps and cord. But, in my days out hiking we got stuck and the 2 mylar packs saved us a night that may have been terrible. They work well in Emergencies.
Amazing how well they work in a bad situation. Thanks for the comments Dr. Ron.
Back in the days that I was a Scoutmaster, we regularly camped during the winter months in NC. One weekend before Christmas at Hanging Rock, the high temp for the day was 9 Degrees F. Slept comfortable by laying a plastic ground cloth, the mylar reflective sheet, a 3/4 length closed cell foam pad, my down sleeping bag (rated at 30), pulling the other half of the mylar sheet over the sleeping bag, and pulling my field jacket over that to weigh the mylar down after I had undressed and climbed in (could have used something else, or taped it, but this worked, and I was being lazy) all beneath a tarp set up as an open-ended A-frame between two trees with a paracord ridge line - unheated. I had learned years before that you NEVER get into you sleeping bag in the clothes you wore during the day - as they are damp with perspiration (even if they feel dry) and cause you to sleep cold. If you can manage it, wear fresh dry socks.
Thank you for this real world info! I love hearing from real experience
I recently used your idea for mylar. I left my 15' sleeping bag at home and took a 32' bag and an emergency sleeping bag. The temp has been unpredictable this year. If it got too cold I would have slipped my bag inside the EM bag, and I knew I would be warm. Turns out, ANOTHER one of your Brilliant ideas lighten my pack by 2 lbs. Dude that's A LOT! Thank you
Sounds great Susan! I am so happy it worked out well. Thanks for watching
I would use option B or E, because i would keep the insulation close to me, and the wind block and reflection as the outer layer. This would make the mylar work mostly as a wind stop, but also a heat reflector for all the insulation layers in the inside.
Thanks for the input and thanks for watching.
Your video was a great success! Lot of intelligent comments.
Great job Dave!
Thank you Garland!
I would say B (or E if you had the option when it's really cold). I had a week of camping, continual rain, and water eventually leaked into my tent so I was forced to sleep in my car. My lightweight sleeping bag wasn't cutting it, so I used a reflective windscreen shade over the top... worked a treat!
Sounds good to me! Sometimes you have to just work with what you have. Thanks for the comments and thanks for watching
Loved the video, loved the comments. Really something to think about and at the same time funny. One of the comments made me laugh till I had tears in my eyes. And you crawling in and out does show the strength of the material. That stuff looks really delicate. And you get in and out of them so well. Thanks for a really fun video.
Oh it does look delicate and rips easy from the edge but held up quit well as a liner. I was actually surprised. Thanks for watching!
Dave you are a genius but your cats are very funny! Keep them in your videos for double entertainment! love what you do
Thanks Paul. LOL, man I couldnt keep the cats away even if I tried!
Wow awesome! You thought of it all, and actually showed it all with them two types used together. I like option E the best to stay warm and not be affected by cold and sweat. I prefer the Mylar not close to my body. Keeping the sweating more at bay. Thanks for sharing your budget knowledge on the fleece bags & the reflective duct tape for strengthening the Mylar bag. Thanks or also showing how fast and easy it is to put in place & get in and out of the set ups too. Looking forward to your next video's as always!
Awesome cats!
Thanks Thomas!
I think this is an internet discussion that we can all agree on.
Great cat video. What did Dave have to say? lololol
This was great to watch again & keep scratchin my head & tryin the combos at different temps in the USGI bivy bag. TAKE CARE..
I'm glad you liked it! It's amazing how these set ups are affected by temperature, humidity, dewpoint and clothing worn. Thanks for watching my friend
I would stay home wrapped up in a woobe watching all of your older videos and not worry about mylar blankets ever. It is hurting my brain just thinking about it. LOL. But if I were going to actually go out there in the cold then I would think that one layer on the ground to prevent moisture rising into my body and then one layer in lean-to fashion over my body reflecting the fire that I would have started several hours prior to constructing the Sleep System. Tada
LOL. I agree Momma. stay home where its warm. I do actually us a Mylar bag like this covering my ground pad often.
Quite honestly I don't know why these things don't come with instructions. I mean if they wrote it on mylar it wouldn't add that much weight to the package, would it? Maybe even some picture diagrams. Perhaps they can invent a type of space blanket that is made with thin iron ore and would magnetically become polarized against the iron ore in the soil and they could create a floating space blanket that would prevent ground convection and that. ...Hey that's a really good storyline. I think that will be the theme of my next novel.
+GG Prepper why you smoke weed and drink beer without us ? ;) some of sfi is going on here :))
No, little one....just life.
respect!
Been a subscriber for a couple of years, luv your channel. I live in the western part of Virginia near the mountains. I’ve been experimenting for years with minimal kit. First in my back yard and then in the mountains. I use a SOL double sized Mylar heat sheet cause it’s bigger, quieter, and resists tears, and safety pinned it to a poncho liner. I reinforced the Mylar with a little clear packaging tape prior to pinning it. By having the insulation on the outside it reduces convection heat loss. I found it to be capable as a blanket or quilt with seasonal clothing to take me down into the 30s. I do not use it as a sleeping bag. It also makes a reflective tarp and under quilt for my hammock with elastic cord. Or if you put a really large zipper horizontally in the poncho liner so you can get your head through it and a horizontal slit in the Mylar reinforced with clear tape, offset by about 6” , it will hang a little lower or even in the back, into a more effective insulated poncho that will also keep you dry. It’s really great to use in natural shelters on a drum liner mattress or foam pad. When I have used a Mylar bivy I have always put a 2 inch hole in the bottom, so that some of the hot moist air can escape from the waist down, and with the large opening at the top, it creates an ok bellows effect when I turn in my sleep. You can also have the shinny side out to create shade, or if it is green Mylar you can reverse it before pining it and put it on the outside and the liner next to you for rain or snow. Of course both can be separated at anytime and used independently of each other in the Summer as tarp and blanket. It weighs ounces and is multipurpose. I am a French and Indian War, and Revolutionary War, re-enactor. I have used a wool blanket in some of the ways just mention, but this better, because it is warmer, drier, and dries fast if wet. Hope this info helps someone else.
Thanks for the comments Kurt, that's very good info!
John Davis made a great point about using non-absorbent materials in conjunction with Mylar augmentation to sleep systems. You've made a point of including a bug net/mosquito bar in your survival kit recommendations. That happens to be one of the very best things that can be used to enhance loft/dead air space within a sleep/survival shelter unit. In very cold weather, folding a large nylon mosquito net bar into an extra layer within your blankets or bag systems not only gives you the non-compressible netting material for air trapping, it also will NOT absorb moisture! As to my personal experience with Mylar augmentation, here in AZ, the winter air is exceptionally dry and I used a 32 degree bag with a silk liner inside a SOL reflective survival bivvy during a February Scouting Snow camp out. 7000 ft elevation, 0 degrees Fahrenheit. I had a Therma-Rest pad under me, but no further insulation beneath. It was still cold, but with layered clothing in addition to the bag and bivvy, I was just fine. Now the SOL bivvy is designed to be less Sweat inducing than straight Mylar, but it also has Velcro tabs along its edges and that allows you to adjust it for venting to reduce sweating. I would tend to agree with the idea of not putting Mylar directly near the skin, but rather outside the rest of the sleeping gear as a weather barrier. Your Fleece - Mylar - Fleece - Mylar option seems pretty solid as it places the layering in the position to repel wind & water from outside as well as close enuf (thru only 1 layer of Fleece) to reflect body heat. Either way, multiple layers that can be adjusted to ANY situation seems the best idea. More Fleece and less Mylar may make sense in warmer or wetter environments, but the point is, you have options if you were to use the 2 Fleece/2 Mylar to enable any of your demonstrated choices.
Fantastic comments and info Kelly! Yes, with four pieces of gear like mylar and fleece it can be tailored to any situation. I'm going to experiment with your netting idea
I did learn something from ur video & the comments. I never thought much about it . I just keep a one in the car for emergency & one in an emergency bag. Thanks. Im glad your working on more videos too.
There a lot to learn from the comments on this one!
Hi there my good friend. This is a great idea for a video. This issue have puzzled me too.
I will follow the discussions here in the comments section. And one day I might test some of the upcoming ideas.
Love your cats! Thank you for sharing this! /Ulrica
Hello Ulrica! I thought it was a good idea to put this all out there and get some discussions going. Its worked so far and lots of differing opinions. I figured the cats would steal the show a lot more than they did. LOL. Stay warm and thanks for watching my good friend!
I am not understanding where all this talk of sweating is coming from. I have "never" sweated under mylar. I want my body warm so I wrap up in it. I have never wanted my face hot or even warm so I leave me face out. No condensation.
I like c seems if it was cold windy,it would keep the noise down,but my knowledge of it is zero. great Video and love how many ways you used it..and yup i'm going now to find the knowledge others have shared Thank You..
Sounds good Mary. Yep, if its super windy the noise really wont matter that much. Theres some fantastic comments being posted here!
for me option C because (and this is just my thoughts and what I have used in my hammock sleep set up in the past) I found when I used mylar blanket as a underblanket then the hammock then sleeping bag I had a damp patch on my back area in the hammock and sleeping bag the temperature was about 8 c.
but the next night I swap things about and used a sinthetic underblanket then mylar laying in that then the hammock a fleece blanket to lay on a wool blanket over the top , that was warm and comfortable and dry.
so what I'm saying is for me mylar has to be away from me enough that my body can breath. Atb jam.👍
Thanks for the comments, makes sense to me. Thanks for watching.
I have used Mylar as an underquilt/windshield in colder hammock use.
My experience, is that Mylar is conductive, and sucks heat out of you on direct contact. It reflects heat that is radiated though.
So when I used it under my hammock, I hung it so that the mylar sagged deeper than the hammock did. That way there was air space between the hammock and the mylar.
I have not tried this below freezing.
Reallybigmonkey1 thanks dave ,like you and many others it's just a matter of trying different ideas out and sharing with others.
Then we all learn more. Atb jam.👍
VanishingNomad thanks mate that's sort of how I used it .
Also find when I have my tarp up its lots warm if I put a mylar sheet under the ridge line pulled out against the tarp on the inside, the side the wind and rain is hitting .
If you get what I mean.
Great video with alot of options, surprising how effevtive this really is, i use Mylar above my ground sheet, makes a huge difference. Thats a whole lot of work... going through those options ! Thanks !! I will experiment
Thanks Steve, I'm glad you liked it! I think I've only scratched the surface of the uses of mylar
I was really interested in this video until i started watching the cats...! Adorable!
LOL, ain't them cats neat!
Excellent video as a research experiment, respect on your patience Dave. I would agree on condensation issues, which can lead to cold, wet clothes & situation depending - Hypothermia.
Thanks, I'm glad you liked it. I learned a lot from all the comments on here
Option E is the only one I could deal with.My best result with milar was to use it as a ridge line tent between the tarp an hammock,at 24deg. F. worked well with little condensation. Too many options! Thanks Dave. ZZ.
Good comment Bro, Thanks for the input and thanks for watching.
Man you sure know how to spark discussions. Excellent talent you have there. I read Lonnys comment on vapor barriers and started looking into them. Found a company named Warmlite. They had the best explanation I have seen about heat loss and cooling for all climate conditions. Well worth checking out. They have a full line of vapor blocking products. Some is quite expensive but the idea is there. Might be fodder for future video topics. Never know
Thank you my friend. Lonnie had a good explanation and a few others did but the discussions are usually "use specific" Like will it be in layers, or as a reflector or to wear against the body to protect your down bag. Lots of uses for this stuff.
2009+/- I basicly did option E on the AT at Bulls Gap. Wind was howling in mid october and cutting through our tent & there was snow on blood Mnt. 2 miles away. I wrapped mylar blanket around my big agnes sleeing bag. I stayed warm as the wind could not get through. In the morning my bag was wet on the outside. I stayed warm and dry. Dryed out bag in the morning and started up trail. My wife slept inside a construction garbage bag inside her big agnes sleeping bag she got damp but stayed warm. She dried out her long johns while hiking. Mylar saved my life as it was cold and probably kept bears away with all the noise. We jet boiled chili inside our tent that night as it was so windy no fire could have stayed lit.
Thank you Jeff for sharing that real world experience! That was the kinda info I was looking for brother!
Thanks Dave for all the videos. It is great watching them please keep them coming.
Thanks Richard, lots more in the works!
This will sound like the Grinch,,, and I don't think of myself as a light sleeper,,, I used the mylar once over my sleeping bag. The noise, noise , noise,,, I could not stand the noise,, and I didn't get much sleep...
I think I will try taping it to the inside of my rain fly...
Thanks Dave,, and keep up the good work....
nice one keep them coming brother
Some folks get freaked out over the noises of the night and the crinkling
Sound might just cover them sounds up enough for them to get to sleep. Thanks for watching Brother!
I'd wake up every time I'd roll over due to the mylar noise... and I'd get claustrophobic from sleeping in a single sleeping bag. I take two sleeping bags and zip them together... then put a couple wool blankets on top... makes plenty of room to stretch out and take off a layer of wool blanket if I get too toasty. Mylar coated Reflectix is good under a sleeping pad... at least 4 feet wide and 6 feet long... cuz I roll around a lot at night sometimes and don't want the ground to get me cold. At least this way I defeat sweating and condensation build up from being incased in a plastic bag.
Willy Bee I fully agree; used a mylar blanket during E&E training but it is noisey as hell. If you are busy wit E&E it is not a good idea. You will also need a dump pouch to pack it away as you'll never going to get it folded away to the size it was before you opened it.
I can listen to you all day such knowledge top man
Thanks!
i live in sweden and camp all year long and B is working real good
Good to hear that my friend!
I value your time, energy and wisdom in your videos. I also adore all the cats "snoopervising".
Thanks Patrice! LOL, The cats love being camera hogs.
2 mylar seems a bit much.I'd worry about sweating too much. I'd rather have it on the outside but not taped up so I can adjust if needed. Good work Dave thanks for sharing.
Sweat is always an issue in certain temps with this material. Thanks for the input and thanks for watching.
You shoulda' said you all should take notes. LOL! I am gonna have to think on this one!!. One problem I foresee is the build up of moisture. I will get back to you. Good show, very thought provoking. Happy trails.
LOL, man there is a lotta options! Get back when you can.
A is basically a reflective vapour barrier liner, often used in winter to keep the insulation dry, as you always sweat some over night and that humidity travels through the insulation and of your bag, freezing on the inside of the outer sleeping bag layer, which reduces insulation properties r night by night.
Good comments, Thanks for the input and thanks for watching.
I took a winter outdoor class and was taught how you lose heat. RECC was the acronym.
R is for radiation, like infrared cameras see; the Mylar will reflect it BUT once it warms up you will still lose the heat as it radiates as well. Mylar: no long term effect.
E is for Evaporation. If you are damp/ sweaty and the moisture evaporates, you get colder. Like a swamp cooler, or sweating in hot weather. But if you have the Mylar against your clothes, the plastic bag keeps the moist air from leaving; Mylar works here.
C is for Conduction. Don't touch the ground or cold things. Mylar has no effect on this.
C is for convection. Moving air can carry heat away from you. Warm air rises, so if you let the air near your skin move away, you get colder. Mylar bag can help: traps the air.
In winter, keeping your sleeping bag dry is key night after night. We all sweat. And in cold weather (like 20 F or below) the air is dry. Your skin sweats a tiny amount ("insensible perspiration") to keep itself moist. That moisture moves away from your skin, into the bag. But it will reach a spot where it is cold enough to condense into liquid and freeze. You will have ice inside the bag. So using the Mylar against your clothes inside the fleece will keep it dryer and warmer. Your clothes will get a bit damp, but getting out of the bag they will dry really fast.
Above 20 degrees, I find liners like this much too hot. Below 20, small liners like these are great as part of my sock system inside my boots. Look up "VBL" or vapor barrier liner.
I've used both mylar space blankets and the 5x7 survival tarps (with mylar reflective side) on many trips. The thinner space blankets were very handy on unexpectedly cold mornings on trips in the Cascades. We used them like a wrap-around blanket and tried not to let too much moisture build up in our clothing. I've used the 5x7 survival tarps under my sleeping pad on nearly every backpack trip in the past 10 years and it really helps keep my body heat from being sucked into the ground. I'm intrigued by your options here! I think that option E, with two layers of fleece and an outer layer of mylar would be my choice. Great topic!
Fantastic input! Thanks for the comments Jim
Option E. The mylar will keep the warm air in and the cold from passing any layer. It will also keep the wind out. Your sweat will be absorbed by the fleece and the fleece is better at insulating when close too the body.
The problem with putting the mylar on the inside is that any heat that goes through and into the other layers wont be able to get back to your body.
Thanks for the input and thanks for watching Raphael
Great video. And I had to watch it twice just to watch the cats behind you. Lol. 😂
Thanks! I'm glad you liked it. Lol, them cats always steal the show. Thanks for watching
Ok...Heres what ive done and can confess to. I made one of those storm shelters with the open front. Basically...the tarp on the ground and behind me with the sides. Kinda like a super shelter without the drop plastic on the front. Got in the mylar bag with my cloths on and tried to sleep. Could barely stay warm enough to even just lay there....never mind sleep. And the noise from the mylar and plastic tarp...I would have rather died. Even contact cemented mylar to a plastic tarp and when I used the same tarp in the summer...heat from the sun melted the glue and the mylar came off. Had one of those half moon pillows...the ones full of beads. I woke up from being in half sleep mode going mad because I thought a moose or fox was right beside me. It was because all the noise coming from the pillow. That was in my hammock. Now...if I were going to pick one of daves options it would be his forever sleeping system. I think mylar belongs in the car for emergincies while one is awake and wants to get warm.. Although something is better than nothing...mylar is just too dam noisy for me. So are plastic tarps for that matter. When it comes to this is what ya got...Ive had far better success rolling up in a blanket and getting inside a giant plastic bag. Not very noisy. Woke up feeling great because I was warm. I suppose id pick the bag...then mylar over that or make a bag from the plastic drop sheet. Id rather do that and be forced to roll up in the sleeping bags and not use them properly than sleep on mylar as a first choice. Just an opinion. Those military systems are great. Sleep right on cold ground without a problem. Mylar is good for making solar ovens as the lining inside...might be good for reflection like a mirror...dont know....never tried. My mirror works great. Mylar....yuk. hahahaha......If I fell through some ice I might want mylar...dont know though...never done that before. Its small enough to carry around though.
Very good story on your experience with Mylar Glen. Ill put your vote in the No column. LOL. Take care brother
I must have missed this when it was posted. I wish I had some input to give but never used mylar in a sleep system. Thanks for taking the time to make the video, it was an interesting question. Take care Dave
Ah no input needed Fred, just sit back and enjoy my friend!
Just one observation: The cold doesn't "get in" as such, it's always the heat that gets out. When you get cold it's because the heat is conducted away from the body.
If you compare putting your hand on a piece of metal and a blanket which are both at room temperature, the metal will feel cooler - even though it's at the exact same temperature as the blanket, because it is a good conductor of heat and will quickly allow the heat from your hand to be conducted away rather than "allowing the cold in" to your hand, whereas the blanket, being a good insulator will not conduct the heat away from your hand so quickly. It's a bit pedantic to point it out, maybe, but it's physics 101!
Cheers, Dave.
Very very good point!
Yes, cold is the absence of heat, not the other way around.
Nilguiri the word pedantic is defined as ostentatious and overly concerned with minute details. I find the word pedantic ostentatious as well since it is often used to impress others.
@@glock907 I'm more of a titmann myself Steve
@@JustaSimplefact i go more for the ass my self it gets me goin ,,lol
All good points to think about, Good job Dave i have read all the comments so far this has been an awesome Community Disscussion
Absolutely. Theres some really good comments pouring in.
at -19 °f in iowa I can say just the mylar itself has help save My life as it has in My prior experiences
Fantastic to hear that Aaron
Have not used mylar yet. Will have to start experimenting. Great thumbs up video as usual. Thank you for sharing
Sounds great my friend. If you have some good results come back and post them here.
The cold will make it through. Mylar is great but it's not magical. Wind goes right through fleece, so I'd put the mylar on the outside no matter the configuration. All that would be toasty in most situations I think. But I think it's not good enough for the deadly temps you mention.
I agree with you, the Mylar will help keep the wind off you. Keeping the Mylar closer to you won't allow the isolating quality of the fleece to work and do it's stuff.
I agree. And the Mylar would help keep dew and rain off the fleece.
I agree. I would do a layer of Mylar on the outside then a layer of fleece another layer of Mylar and a final layer of fleece on the inside.
I would actually make a giant fire. :D
Thanks for the comments, makes sense to me. Thanks for watching.
Really appreciate all the thought and explanation that goes into these videos, as well as the intention to build a knowledge base from the community. My own experience with mylar, as demo'd in this video is that sleeping in this bag can be really noisy, though warm. I use a single mylar sheet under my Wiggy's bag when in freezing weather, right on the floor of my tent with the Wiggy's on top, to sleep well. No crunch, crunch during the night. The extra $ for the Wiggy's is well worth it.
Thanks for the comments. I always love input from how folks us this stuff
I've used it over my one man tent then I put one at the bottom of my tent my tent was a summer tent my bag was good to 40 I was camping in below 20 next to the river and stayed warm the only condition was on the outside did not get in the tent I don't know if that's the beat way but it worked out well for me
David, you always seam to give good information in your videos. You help others to learn the camping skills to have acquired thru out your years of experience. And, I am grateful for this shared knowledge. Thank you for your videos.
From all I have read and been told about proper use of a space blanket, I would not use them in the manor you have illustrated for fear of getting hypothermia during the night. No matter what you want to call it, sweat or perspiration, all mammals continually loose body moisture every minute of their lives.24-7-365.
An emergency blanket, sometimes referred to as a first aid blanket, space blanket, Mylar, thermal or weather blanket, is used in emergencies to reduce heat loss in a person's body caused by thermal radiation, water evaporation and convection.
Cold air tries to carry your body heat away. Blankets form a barrier between your body and that cold air. Since heat doesn't transfer through the blankets very well, they keep the heat from getting out. The colder the surroundings are, the more insulation you need to keep your body heat from escaping too fast.
A space blanket (also known as a Mylar blanket, first aid blanket, safety blanket, thermal blanket or weather blanket) is an especially low-weight, low-bulk blanket made of heat-reflective thin plastic sheeting.
In my humble opinion, these are the only methods in which to use space blankets. Use the shiny space blanket between you and the ground to prevent heat loss. Lay your sleeping pad on top of the space blanket. Then, lay your sleep system on top of the pad. Finally, lay a second space blanket over the top of your sleep system if you are not going to have a fire. The space blankets work best with 4 to 6 inches of dead air space between you and the blanket. DO NOT use the blanket in a bag form for extended period as they will trap escaping body moisture and you will start to get hypothermia. When using a fire, setup the blanket on an angled wall (30 to 45 degree angle) behind you with the fir burning in front of you with a second blanket on the ground and your sleep system on top of it. The radiant heat from the fire will be reflected off the space blankets back to your body warming you up. Think of yourself ass a human burrito in a reflector oven. To minimize heat convection loss a good layer of dry lofty materials is best placed between the ground and the space blanket.
I hope you and your family are doing well.
Thanks for the input Richard
Always love your videos man, keep going!
Thanks!
I can only relate my experience. As a long-distance ultralight thruhiker I have tried many things to keep me comfortable at night. My sleep system as it is is good to 10 degrees. I have been on hikes where that wasn't enough, whether because of rain,snow or wind. I always have a mylar blanket with me. As a gram weenie I evaluate everything that I carry and it is always going to make the cut. I've tried it in many configurations and settled on wrapping it around my airpad and laying on top of it in my bag. Everything other way I have tried produces condensation. Being on trail for weeks and months at a time my biggest threat is always going to be moisture. If not a direct threat to hypothermia then I have to stop and dry my gear or carry it uselessly wet on my back. Great vid!!!
Good use of it Dave. I'm glad you liked ithe video, Thanks for watching
I'd only ever use one in an emergency situation to block wind and trap heat. I have a grabber that I use as a ground cloth in the winter and have noticed no difference using it face up (reflective) or face down (conductive). Option E is your best bet to block wind, trap body heat and conduct heat towards you. My advice is carry a better system, learn how to build a shelter and use fire to your advantage. There is no sense in trying to patch something together when there are warmer and more efficient options these days.
Thanks for the input and thanks for watching Brother
Ben you are lol over you tube from living survival camping with Chris and will from prepared mind 101 and mantas outdoors. David Did aka a point of using 6 different methods of using the Mylar tube tent as a sleep system. My concern I that someone my use this system in the wrong way example is maybe a boy scout or a first time camper going out into the woods thinking they are doing something right turn very wrong. Most people get hypothermia in wether between 40 and 50 degree Fahrenheit. I believe David's intent was to help keep people warm with different options and no intent to cause anyone to get in further problems in the wood camping. We are lol in this together and let's have fun next lol be safe.
with all respect , William , your comments supporting the SOL Bivy Bag down to below 0 F and sweating is somewhat questionable at best , , and a downright a great stretch of the truth at its worst. . I won't directly challenge you for now , , but I have a SOL Bivy ... I've not had to use it yet , but when I ever do , I'll let you know how it comes out. In the meantime , I don't hide behind a mask , , so I ask ' why do you ? '
lol I'm not hiding behind a mask my kid did that for me years ago so I left it. I am a 52 year old man with about 200 camping trips under my belt of experience from around the world. When Mylar blankets first came out they were sold as emergency space blankets that were used by NASA for pilots and astronauts. The time I hunting it was almost zero degrees I was not car hunting I was 3 hours walking up a mountain on state land. It was windy and it was cold so you are warm and cold when you stop for a minute or two. If you ever opened your sol bivvy you will see it is breathable it is not marked waterproof but I have used it in rain and had my feet out side my tarp I was not wet. but still you will sweat so if you use it friend you may have to take your jacket off but it is a good wind blocker
I have used the sol bivvy as a sleeping bag about 15 times and the coldest I have had it as a sleeping bag wearing just a marine corp Happy suit
Hi Dave !! Another great video that is sure to get the discussions going. The comments I have read have been very informative and thought provoking. I like the single or double bags with the mylar on the outside. I think we need some really cold weather so the testing can begin !! Thanks for a really good video. My family loves you cats !!!!
Thanks Ellis, I'm glad you liked it. Well some comments are good, some bad. Some folks are even attacking me because they think Im trying to teach how to use mylar. I dont know, thats why Im asking! LOL. Who can go wrong with cats? Thanks for watching
the advantafe here is lighness and being prepared for an unexpected cold situation while traveling. once i went to visit boston in july and took a train to rockport at the end of the day. the train stopped at Rockport and i had to exit the train at midnight. walking towards the town a policr car pulled up and the officer asked me where i was headed. i told him to get a room. he said you best head back a the rooms are taken. thus began the worst night of my life. il take one mylar and a liner please. and one a them cats.
Good story. I would hate to be stuck out in the cold up North.
After 5 years, I still do not know the best answer!
But this discussion is interesting and useful, and the most important result is to teach people to understand the layers'concept and the reflective / insulating / water-resistance / wind-breaking / moisture-wicking properties of the different materials, and allow one to take the best decision based on location, temperature, wind, rain, humidity, sex, body mass, methabolism (people with hipothyroidism have very little resistance to cold), what you eat at night, the kind of protection you have with you, how mobile you have to be or how long are you going to stay in the same place...
Thanks, good luck to all, praise may be the Lord as His birth is to be commemorated tomorrow, and may His peace be with everyone!
Very good comments! To me the biggest factors are humidity vs. temperature and how much does the individual sweat or not sweat when sleeping
1) *You ALWAYS "sweat"* -- otherwise, you're dead. Mylar on the inside will prevent that sweat from hitting your insulation.
2) *mylar fleece fleece mylar* -- reflective, convective convective, and then the second mylar: MORE convective (anti-breeze). The two layers of fleece provide the majority of your convection-slowing insulation, but you still have all that open weave ventilating hard-won heat to the sky. Hence, the second mylar on the outside -- not as reflective protection, but this time as wind-stopper.
Thanks for the input Thomas
Another good one again Dave, information is knowledge,and knowledge is wisdom.
Loved the Cats in the background, my Cat is sleeping next to me,i can feel the heat from her!!!
Thanks Tom, I'm glad you liked it. Thanks for watching
Every time I've tried to use mylar I've ended up damp. I think I would go with fresh, dry clothes and option B. If that wasn't enough I'd go to E. My thinking is that the mylar on the outside would also act as a wind and water resistant shell. Either way I'd expect to wake up wet.
Thanks for the input and thanks for watching Steve
Per usual, David, you produce a very watchable and enjoyable video. I like your work on variations.
Here's my input on Mylar: First, and I share this because I have been corrected on it, Mylar itself is just the polyester plastic. It is the substrate for the the aluminum, which is the really effective "ingredient". I call the whole Mylar and aluminum product "Mylar". I think we all do. Mylar will insulate you no matter whether it is next to you or separated from you by other materials. It's sole purpose is to block convection and reflect infrared. It is absolute crap for conductive insulation. I think most people know that last part.
In most situations it is best to have the Mylar on the outside to create a windbreak. The two exceptions to that occur for specific reasons:
1. If it is an emergency and you are trying to warm a person up, then it is best to get the Mylar as close to the body as possible(faster heating) so that the infrared is being reflected onto your skin rather than onto your insulation(slower). Once your subject is warm it is best to have a layer between them and the Mylar to reduce the eventual moisture build up.
2. If you want to protect the Mylar from damage, then you have another material between it and the outside world.
The thing is that every permutation you show us will work, but will be varying in effectiveness, based upon the elements and purpose. If I was tasking myself to create some sort of bivy with the Mylar(that will last), then I would have a fleece/wool layer on the inside, Mylar on top of that, then some sort of durable material (wool or synthetic) on the outside.
One thing people seem to forget is that Mylar is noisy. If it can be sandwiched between materials it will be muffled and more tolerable as you try to sleep....or stay hidden.
Very very good comments and explainations Chris! And may I add its great hearing from you again brother!
No matter how long I am away from youtube, when I come back, I head straight for your channel. :)
The noise that mylar makes would drive me absolutely crazy if I was trying to sleep. I agree with Survival Russia. You are better off with a material that will breathe and allow condensation to escape.
Thx! This helps me bunches! The concepts are simple. Colorado snow and wind are a challenge.
Thanks Chris, I'm happy it helped!
I don't use mylar but i would use it more as a heat reflector! But i think the proper use is what you think it's best need at the time of use!
Thanks for the input and thanks for watching.
Any time Dave!
Dave you surely got your daily workout crawling in and out of those things. Personally I would go for Option E simply from the standpoint that the mylar looks like a bear to crawl into and keep from bunching up. Thanks for your hard work and take care brother.
LOL, It was like a work out Scott! Thanks for the comment and thanks for watching
My first introduction to this product was after the marathon in New Providence, RI many moons ago where those of us near death were given a "blanket" and pointed in the direction of the medical tent. It did a fair job keeping my heat in as I moved but I would have preferred a sweatshirt. Every time you moved the cold air would blow in and remove the heat you were trying to gather. Once I was stationary on a cot it did a much better job and I was able to recoup relatively quickly. I learned three very important lessons that day; 1) Don't run your second marathon 6 weeks after your 1st... 2) Don't run your BEST EVER 20 miler in a race that covers 26.2 miles! and, 3) "THE WALL" is not something you can see but it is definitely a physical reality and will cause you to slow down to a crawl when you hit it. I actually didn't learn much about mylar blankets but I would suggest they would be good to keep on hand for any emergency where a patient needs to be kept warm and can be kept still. : )
Thanks for the comments, makes sense to me. Thanks for watching.
Gotta add: LOVE watching your beautiful kitties playing in the background. A wonderful yard for cats!
LOL, they kinda make the video
Good uses and ideas David. Cool as usual ;)
Thanks Sepp! Thanks for watching Brother.
Hi David. In your usual form, a great video. THANK YOU. I choose option E. It's probably advantageous to have the Mylar away from the skin and the fleece near the skin for wicking. Best wishes!
Thanks for the input and thanks for watching.
new name "Reallybigbakedpotato"
I have no experience with Mylar really, but my opinion is, with option A, with the Mylar inside, if you were to sweat, it could pool up, at lease with the fleece first, there is something to absorb moisture. though if you're warm enough to sweat, you won't be cold, but its not very comfortable to sleep in a pool of sweat. lol Depending on the situation, having fleece on the outside, would allow for the outer layer to get wet, and freeze.
I would choose option E.
lmao
Thanks for the input and thanks for watching.
:)
milar as an elcheapo floor mat between ground and your self infl sleep mat. As you said, the ground sucks the heat out. As we use it for camping and not for emergencies. You also dont need to worry about it ripping so much either. They are as cheap as a packet of sweeties, way nothing and you can have 3 of them easily at hand. Scottish winters have been mild past 4 years and milar has been in my pack everytime. I am a lizard that needs to heat up on a hot rock of a day, so trust me when I say these are efficient. Thanks for the video Dave, glad to see you have shaken off the flu.
Thanks for the comments, makes sense to me. Brother I think Im getting sick again! Thanks for watching.
That's cat stole the show 🐈
I guess he's never heard the old performer's adage "never work with animals or children"! :-)
What i know about heating and insulation, your best bet would have been option H. That would be mylar, fleece, fleece. mylar. or in heating and insulation terms vapor barrier, doouble layer insulation, vapor barrier. Love your channel. watch you all the time.
Good comment! Makes sense to me when you look at in in terms of vapor barrier and insulation. Thanks for watching Debra
So.. Option "C". It what I have used for years in my "two wool blanket" set up. I know people balk at the "weight" of wool - but two wool blankets with Mylar in-between... well you "could" sleep out under the stars in rain with that...
I got a wool (80%) blanket recently and I could not believe the weight. But I love the durability, antimicrobial properties, its crazy ability to keep you cool or warm, and to wick moisture away. I used wool for cloth diapering and as long as my covers were well lanolized all i had to do was air them out and they could go on like that for a long time. Nothing else can do that!
Fantastic comment Troy! I was wanting to hear from real use experience. Thanks for the input brother
Journal Of A Wimpy Prepper-Question #1: Is the main purpose you lanolize for less water weight from absorption? Q.#2: Does lanolized wool create more of a fatwood effect than non-lanolized? We thank you for your suppor, er, response.
I personally like to use my tarp shelter with the inside lines with a Mylar blanket of some type and then have a 1/2 circle Mylar wall some where around 3 ft. tall which reflects most all your heat into your Mylar lined shelter and I sleep in various configurations of the USGI 4 part sleep system with a sleep mat. I've used this setup on many occasions in very cold weather and always stay comfortable. By the way Dave, I love all your ideas and videos...keep'em comin! Maybe someday we'll meet and do a cold weather camp out!
Brother I love hearing from real world experiences with this stuff! Maybe Ill see ya in the woods one day. Thanks for the input and thanks for watching.
Definitely option E. Wind blocker on the outside. :)
Thanks for the input!
Really enjoyed the video. Thanks for all the hard work and taking the time to make it. Keep them coming!!!!
Thanks Kippy!
Great video! We have missed you! I am amazed at how easily you could crawl, wiggle, slide, slither, squirm, wriggle, twist, whatever you call it :-) in and out of those Mylar blankets! You were doing some serious Monkeying around for sure! I probably would have needed Nick to place his foot at the top of my head and push me in. LOL Like I said, interesting video and great information. Thank you so much for uploading it. :-)
Thanks Lyn, I'm glad you liked it. LOL, all that wiggling and twisting keeps me young. Check out some of the comments on here, they are pretty educational. Thanks for watching and may God bless you.
Oh I have, and you have got some excellent comments on this one for sure! Stay young at heart always! God bless you, too! :)
i would use two fleece bags together and put mylar on outside.but also put holes in mylar to let moisture and humidity out.no matter what you do you will get moisture.anyone who has ever slept in a tent sealed up or a vehicle with the windows up in the winter knows you will get moisture.the mylar works by reflection so putting holes in it will allow some moisture to escape but cut down on amount of heat reflected.i personally would only use mylar on top or side of tent or shelter.not on my body.keep the vids coming bud.love your work
Thanks for the input and thanks for watching. See ya in the next one Brother.
well during our training we were told to just wrap the blackest loose around us and sit ! now IV only had a chance to use it 3 times it was warm but it was wool mylar wool 1st time 2nd time it was just mylar 3 Rd time was I use it as a ground cover
1st time warm 22 deg. no fire toasty
2nd time28 deg not to bad warm but not hot
3 Rd time sucked don't lay directly on it has no heat value 35 deg btw
but what you done there is made a sleep system bag mylar bag should be good to 25 or so and bag on top should give another 10 deg
now sweating is an issue but with clothes on your right I believe it would keep the sweat warm water is also a insulater if kept warm but given the fact that we were trained to make it loose to make a cocoon around you of warm dead air bag mylar bag should work great hope that helps say hey to Nick for me stay safe brother
but mylar supposed to be as close to your.body to reflect heat so the heat lost through the fleece would circulate back into the fleece and then to you at what temperature ? not sure depends on how much heat you give off then there would be the condensation between the layers as you said keeping the moisture warm I think you'd still get thin layer of frost on the mylar just be cause the air coldness on the top of the mylar but open top bag LEAVE ALOT of air out so maybe there won't be as much condensation anywhere
+kabaruser Try using periods. They end one sentence so you can begin another.
ya but it makes for interesting reading. besides this is about mylar and what not .! not about my grammer.
+kabaruser When people read it, it's not easy to understand if you don't use periods you have to slow down and study the context to determine where one thought ends and the next begins besides that it also shows laziness and is contributing to the stupidity of society. Is it really that hard? because trying to read and comprehend sentences without them actually IS hard. Is it a lack of respect for others?
+IDOALL It's called "punctuation," it's not "grammar."
Your video got me thinking. I got out my cheap Coleman fleece sleeping bag liner laid it out on the floor.Then I secured Mylar to it with carpet tape. Two strips about 2" long at the bottom, four strips along the zippered side spaced evenly apart and two strips across the top of the liner. I didn't bother securing along the forth side. I would have preferred to use Velcro for the strips but didn't have any and don't know how to sow (yet). That would help when it comes time to wash.
I'm going to tryout this method with a Mylar between me and a cheap sleeping pad. Also, I like the two Costco Black Diamond Quilts I bought recently . I may be adding a Mylar sheet on top of the sleeping quilts.
Thanks Bro, the video.
Sounds great! Nothing beats experimenting yourself and seeing how it works for you. We all sleep different in differing conditions so you may just find something that works. Thanks for watching
hey dave , i have made a over quilt with mylar sewed between two layers of cloth . it works great for bouncing heat back on me.. you can bye this mylar at joanns fabric by the yard, and it has nylon insulation attached to both sides of the mylar.. if you can't find it , i will send you some for testing ..
..bill
Man that sounds cool! We have a Jo Anns not far from here.
Thanks for opening this very interesting discussion Dave, it may just be a very useful reminder to us outdoors types , that we need to be better prepared than we often are, (I am guilty of this too!) my down sleeping bag packs up small, it's lightweight and I don't use it enough. I will remedy that.
Thank you Dave.
You are very welcome Brother. I am loving all the comments thats coming in. Theres a lot of good points being brought up
I'm a old farmer, wool retains heat when wet, why fisher men, farmers , etc use to use it. Itchy yes, warm yes, option B with wool yes, insulation between you and the ground yes yes yes, but what do I know...I survived farming lol
Hard to argue with wool. It worked forever
Hi i have no heat in the rental trailor. The heater i bought broke an the heated blanket broke the electric stove was little help, but 2.70 mylar blanket i bought at Walmart really helped to keep me warm durning the wintet storm we just went through so glad i boughr them. First its a twin fleece blanket then the mylar on top of that then 2 more twin blanket on top an BAM!!!! Happy Happy Happy. So warm an cozy.
Thanks for sharing your experience Corina!
everybody mylar does not reflect heat, it reflects light, which can heat you if it's trapped in the bag. I keep seeing comments of it reflecting heat away from you, NOT POSSIBLE... it honestly works best with mild airflow so that you don't get soaked in your condensation, if not possible, put it close to your skin so that you get wet and not your insulating blankets... the tent configuration works very well and probably the best depending on the door... i have one with a mesh door and Ive slept in it many times ice fishing down to minus 20 Celsius... i just take off my shell layer and roll up in a moving blanket ontop of cheap sleeping mat
I agree that it reflects light (which helps to heat) but it DOES reflect heat as well. That's why foil is used in cooking.
Iam1uglyguy it can help trap heat but can't reflect it... heat is just the energy that a material has through vibration... which can be lost by passing the vibration to other materials, emitting light, or chemical change
The heat that radiates from your body is infrared heat...and infrared is a designated descrption for part of the electromagnetic spectrum. It is a form of light, but at such a low wavelength, our eyes cannot detect it. Our skin, however, can detect it through the way it warms our flesh. That's why in infrared (thermal) imaging, your body glows brightest on those video screens where the bodypart is hottest, or where the metal is hottest on an object that's been held in the hand long enough to stop being cool.
Heat and light in this case are considered to be essentially the same thing when it comes to the mylar's reflective capabilities. It IS reflecting heat. It's the same thing, and is capable of being simultaneously the same thing. It is both infrared radiation in the electromagnetic spectrum (light), and infrared radiation (thermal energy, heat).
Iam1uglyguy also foil is used in cooking to trap moisture and to keep things hot, not to make them hotter
ladyofthemasque they are not the same, and no scientists considers them the same, heat is the energy a material contains through vibration... No mirror in the world reflects heat... All light frequencies are the electromagnetic spectrum, infrared is just a portion, ultraviolet is another portion, visible spectrum another portion
okay here's my two cents. the video was educational you had some really good ideas. I myself will probably never camp like this but in an emergency situation it is good to know. you inspired me to get off the couch and start going outside. even if it's just in the backyard practicing how to start a fire with a bow-drill... I love all of your videos thank you for all your hard work and time you put into them.
Sounds good Tony, get out and test, practice and experiment any time you can