Another nod to the Blizzard Survival Blankets, they seem to be used widely by other the armed forces, including in the prevention or treatment of hypothermia:
http://www.blizzardsurvival.com/section.php/2/582bad659b926643f881f6e7b5c317f8

I suspect you could get 25 of these into less space than what I think from your intro is 12 regular survival blankets would take up. (or maybe not now that I see they are 'just' space blankets ;-) )