We have been making paco pads for over 28 years now, and They have made their way to Antarctica, gone across Greenland just recently, and been on numerous dog sled treks in the Northwest Territories of Canada. The whole idea is to use foam that is either firm enough or thick enough to keep the cold from coming up through the bag. By the way... It is nice to see that some people get it. The pad can protect the bottom of your tent too, so if they are too big, just pitch the tent on top of the pads. That whay when the tent flies away in the wind, the pads are still there save and sound. Paco Pads now come with Corner Condoms to protect the corners of the pad from wear.