"survival" blankets

Hoodoo said:
You ever buy one of those tiny space blankets? They are like paper. And try unfolding them in the wind!
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there's no wind in space!

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big goldish square at an angle at the top of Skylab is probably THE original space blanket.


if you want something heavier than the plain mylar space blanket, but lighter than the heavy duty "sportsmans" blanket, find a USGI "Combat Casualty" blanket. it's matte OD on one side, silver on the other and it's much more compact than the heavy duty version.
 
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Shotgun said:
So do you sleep on the bare floor without any kind of padding?
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Just a rug. It's very comfortable once you get used to it. Folks in Asia have been sleeping on bare floors for thousands of years with no problem. Beds are a Western contrivance, as are couches, chairs and the like. They eat up a lot of otherwise useful space. As Asian countries become "Westernized", folks are starting to use beds and such. But the old-school way involves very little furniture at all. Just low tables, which you sit on the floor to use, and they fold away when you're not using them. If you get a "traditional" room in a Korean hotel, you get an empty room with a big flatscreen TV on the wall, with a closet containing blankets, pillows, and a folding table.

My in-laws' bed is literally a slab of beautifully figured granite, with heating elements underneath, that you can control by zone with a touchscreen.
 
If you do a thread search you see that the preferred type and brand is the Adventure medical Heat sheets.
 
I've only tired one type of rescue sheet. Its made by Spencer Medical, an Italian company.
Made from aluminised polystyrene and measures 63x86" (120x220cm).
The good thing about this is that it isn't fragile at all. Definitely more solid that the one Ron Hood talks about 9 years earlier in this thread.
The material doesn't crush, crumble or tear like foil, but sort of springs back to shape. You can use it more than once.

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They also make a larger, heavier, and more durable model that looks like a tarp.
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I have 3 Heat sheets. One in each car and one in my kit. But I also have several of the mylar ones scattered about. Better than nothing.

Paul
 
I did a 5 day trip a couple of weeks ago with only a survival blanket and an AMK heat sheet... they performed surprisingly well at temperatures just above freezing as long as I took care of providing natural insulation underneath me. They are a nice combo with a firebed too, providing a vapor barrier from below and reflecting heat back at my topside...

they do collect condensation amazingly well, however, so care must be taken....
 
Heres a "experiment" I did a couple weeks ago with a Heat sheet as well as and GI issued blanket

I was reading about Mors Kochanski's Super Shelter last night and got to thinking.

I had just picked up this Trekker brand bivy tent at Goodwill, and thought can a the Super Shelter theory work with a normal tent.

I set the tent up with one side facing south, as to be in the sun all day.

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I then rigged up my thermal blanket from end to end across the ridge line fo the tent, using the attachment points already in the tent. I must say it was almost too easy to set up. I pulled it as taunt as possible and formed it to the shape of the north side of the tent, with the refective surface pointing South.

Placing my therarest pad and sleeping bag in the tent as if to warm it for a nights sleep. And then placed a indoor/outdoor temp gauge in the middle of the tent. Placing the other sensor just outside the tent, about a foot or so.

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Then a minute later checked to see if there was difference in temp already,

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10 minute mark:

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30 minute mark:

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1 hour mark: Hard to read, but it says 128!! And the ouside says 82, I would think the tent is reflecting heat to it as well as outside temp is 68.

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I would say its working quite well!!

This could be used on a winter day, in the sun to warm yourself with little effort. I will try it with a fire at night as well to see if the theroy works that way as well.

And tonight I will be sleeping in it to see how it works just holding body temp heat in, and if it helps or hinders.

More to come later.


Well last night went very well, in my opinion. I was warm and toasty all night! But it didn't get that cold outside :(


I ended up going with a fire, I set up another reflector on the otherside of the tent, this time using one of the heat sheet style blankets.

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Got the fire going, and cooked up some bannock and tea! As to not waste a prefectly good fire!

Here's a view from inside one looking down the tent as I lay in it, the other looking out the door at the fire.

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The warmest it ever got was 91,

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And the coldest was 57, after the fire died down.

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When I got out of bed this morning it was 39 outside and still 57 in the tent, Not bad at all.

My experiment went very well I think, I would do this again in the field.

But I made sure it was dead calm night as I really didnt want to wake up with the tent on fire!!

Things I would do different, is ad a clear plastic piece between the tent and the fire, not only to help trap the heat but to act as a spark/ash guard for the tent.
 
TLM said:
Radiation heat loss is at maximum on clear dry nights and the higher you go the greater it gets, at 3000 m it can be double compared to sea level.
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Leave it to me to try and get into an argument with a post that is 9 years old :D :D :D

I thought it would be useful to clarify the points above which I think are sourced from Ron Hood and are factually incorrect. Ron Hood has a video about hypothermia which is generally quite good (as all his videos are), but then he talks about radiation heat loss and states almost word for word what TLM states above. The explanation is completely wrong, although the practice and application advocated by Hood and TLM in the other parts of his earlier post are correct.

Radiation is produced by any body of matter which has a temperature greater than absolute zero (i.e. all matter in the universe). For relatively low temperature objects, like human beings, the radiation given off is in the form of photons of light in the infrared spectrum. These photons are produced when electrons from atoms in the molecules of the body fall from a high energy state to a low energy state. The wavelength and energy content of the photons lost are largely a function of the makeup of atoms in the body. The number of photons produced are largely a function of the temperature of the body. Humans are homeotherms (were talking about being warm blooded here) and of constant body temperature. We also tend to be of similar composition in terms of the atoms making up our body, so the amount of irradiation produced by our bodies remains fairly constant. In other words, whether or not it is cloudy or clear or the what the elevation is has nothing to do with radiant heat loss by your body. These factors might be correlated with relative humidity of air or likelihood of encountering wind which can influence heat loss by convection processes.

By and large, radiant heat loss from humans tends to be smaller than convection and conductive heat loss. However, as rightly pointed out, sometimes every little bit counts and collecting that extra 10 or 15% of heat loss via a reflector may make things better. Alternatively, high temperature objects like Sun's and fires emit much larger percentages of energy in the form of light. Also the light emitted from these bodies dissipates in air at a much slower rate than heat. Therefore the use of reflectors to harvest this energy at a further distance from a fire/sun can be highly effective even if you can't feel the heat directly the radiating body.
 
coyotlviejo said:
Placing the space blanket under you would only help as a moisture barrier, as it is not designed as a thermal reflector. It works as a radiation reflector, catching radiated heat and/or light and bouncing it back at you. Because of this it is better if there is a space between you and it.

I used one once when all I had was a medium-range sleeping bag and a tarp and found myself at a much higher elevation than I had anticipated. I put it over my sleeping bag and pulled the tarp over the whole deal for rain protection and slept comfortably all night long - even though I woke to find the tarp frozen stiff and ice coating everything around me. In fact, I even had to unzip my sleeping bag and stick a leg out to cool down!
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Radiation is thermal (which means heat). I think you mean they are not designed as an insulator against conduction (object to object). Such as your body on the ground...
 
michaelmcgo said:
Radiation is thermal (which means heat). I think you mean they are not designed as an insulator against conduction (object to object). Such as your body on the ground...
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Ha, I'm not the only one arguing with old posts :D :D :D

Radiation is light and it is only converted to heat when a photon of light is absorbed by a body of matter. Thats why space blankets don't heat up when you put them in the sun, the reflect all or most of the light (visible and non-visible) away the reflective surface.
 
KuRUpTD said:
Holy smokes - a thread revival from 2001

I prefer the AMK heatsheet myself

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Me too. These are much more robust than the little cheapo ones, although I keep some of those around too, along with some 55 gal. drum liners.
 
kgd said:
Ha, I'm not the only one arguing with old posts :D :D :D

Radiation is light and it is only converted to heat when a photon of light is absorbed by a body of matter. Thats why space blankets don't heat up when you put them in the sun, the reflect all or most of the light (visible and non-visible) away the reflective surface.
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I think you're the man for the job on this one, Dr. KGD. My military training was simply something like "if you have a space blanket or a casualty blanket (the heavier kind with a tarp on one side), wrap yourself in it, use it as a poncho for shelter, or use it as a reflector for signaling."

I was reading some of Kochanski's work (one of his little pamphlets actually) and he stated at one point that the space blanket is best used as close as possible to the body without touching it. Do you find that statement sound?

Obviously there are other uses, such as keeping the rain off, stopping the wind, or creating a microclimate by wrapping it around oneself and trapping some air which your body will heat, but those are merely funcitons of the space blanket being being nonporous and not the reflective nature as I understand it. In other words, a clear piece of plastic would be just as effective in those roles.
 
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kgd said:
Leave it to me to try and get into an argument with a post that is 9 years old :D :D :D

I thought it would be useful to clarify the points above which I think are sourced from Ron Hood and are factually incorrect. Ron Hood has a video about hypothermia which is generally quite good (as all his videos are),
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Double Hah! Doc Ron in this thread IS Dr. Ron Hood. :)

I too find his videos to be outstanding.
 
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So if I understand this, all radiant, no insulative properties. Completely worthless on the ground underneath a pad, but over the top close to the body, good to go. Interesting stuff! I might have to take the temp gun out and test some of this as it sounds intriguing. I know the hammock reflector has been explored before, but I might have to try and pin one of these right underneath the hammock to see if they work better...herrmmm. Cool post
 
I also think it is a matter of chosing a good one, cheap, ultra compact ones just won't do the job.

Down here I can only get either Coleman or Coghlan's. The compact Coleman is not even rugged enough, feels just like silver plastic.

On the other hand, the large Coghlan's Survival Blanket looks great, had not had a chance to use it but it feels tough and very resistant. It's also standard equipment in the local Red Cross ambulances. It's quite large, though, not the kind of thing to put in a kit but in your backpack.

I have yet to try the compact Coghlan's Blanket (The Survival bags are not as good)
 
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