There is a survival type blanket at wall-mart that cost like a buck or too. Like an emergency blanket, I have not seen these myself but several others say they have them. There made from 2-mill Mylar you may need a few of them but at that price it's ok. You can order some from eBay as well it's cheep there too and you can get in rolls. Just make it easy if you buy a roll then make sure you get a wide one it's easer to deal with. 1-mil thickness is ok but it does rip easy.