補充一下R value
R-value describes an item's resistance to the flow of heat. R-value quite literaly is the (ft^2*degF*hours/BTU). If we all had a lab this might make a difference to us, but where R-value really comes in handy is when comparing mats. It is a tool when you want to compare apples to apples, and figure out which pad is best suited for your activity. You might have heard R- numbers tossed around the last time you were at your local hardware store talking about insulation for your home. The higher the R-value, the slower heat leaves you. So just as you want your home to be efficient, you also want your outdoor sleeping system to keep you warm.