At our local community college, the Rec instructor had a survival night, live like a hobo so to speak. You spent the night out in Sept., lows could be freezing or in the 40F's at least, sleeping in either your clothes or what could be found. I suggested to a friend to use two boxes with wadded up newspaper as the insulating layer between the two boxes, one of course smaller than the other. He did pretty good. The instructor checked everyone in in the PM and at about 6AM so they could get to class or work.