While camping one weekend I saw someone using these on their pop-up pop-outs. When I asked why they said that they reflected the heat and kept the camper cooler during the day. I found these at my favorite on line store Big O and bought them. We've only had a chance to use them one time but they did exactly what I wanted them to do, keep the heat out of my camper and ease the work load on my A/C. The only thing that would make me happier would be to have them in a little larger size. I can't comment on their original designed usefullness but they worked for this warm camper.