I've always wondered why they don't make a huge sealed "bag" of something like the heatsheat - not to sleep in, but to lay on. I think the mylar would never be strong enough, but couldn't you get a very thin and light "air mattress" out of two AMK Heatsheets sealed at the edges with a blow-up valve? Seems like a nice emergency alternative, but the Mylar would do. I can't remember who, but someone here spends a lot of time evaluating these things. <img src="/images/graemlins/smile.gif" alt="" />