Undergarment

[john j]

I have tried them and found that they don't work too well. They need oxygen to work and if you are using Ar to fill the suit, they fizzle out pretty fast. You can get the gel-pack kind that are re-usable though and they do work. You have to microwave them or boil them in water which dissolves the crystals inside making them ready for use. When you want to use them, you press on a metal tab inside the gel-pack and it starts to get hot and lasts for a while. You can then microwave them again to re-dissolve the crystals and they are ready to use again later.

Give your idea a try, but when I did that, it didn't work all that well.