Space Blankets

[newforest]

I learned something new this winter....if you put one of those reflective silver space-emergency-survival blankets under your tent or just under your sleeping bag, it reflects your body heat back up to you. I put one under the thin mattress that came with my cot the other day, and now each morning it feels like I'm sleeping on a heating pad.

A $4 investment.

Putting one under a tent would also keep moisture from wicking up too but I think would decrease the life-span of the cheapo 'blanket'. I bought one at an outdoor mega-store, a brand specifically sold for camping use these days. But I think they still sell them lots of places for keeping around in an emergency. I doubt I'll ever camp in the winter without one now.

[salbrecher]

Radiative heat loss is only part of where you are losing heat from. If you have a good sleeping bag, radiative heat loss will be minimal. putting a space blanket under a thin mattress will not help conductive heat loss through the floor. Imaging wrapping yourself in a space blanket and and lying on a cold cement floor. You will prevent radiative heat loss but will still get very cold as so much heat will be lost to the cold cement. A well insulated mattress is just as important as a good sleeping bag in cold temps. I guess as long as you THINK you are keeping yourself warmer, then that is all that matters...

[newforest]

I have an awesome sleeping bag ... US Marine Corps 'Mountain Issue', kept the Leathernecks alive at Chosin Reservoir. Jam packed with real goose feathers. But I can tell in the morning where the space blanket has slipped away from, cuz that part is colder. Everyone on my crew that has tried one says the same; no more sleeping without one when the below freezing nights roll around, and we have had way, way too many of those this year.