I have a question about the wear and tear on clothing that occurs in the dryer. Is it caused by the heat, or by the tumbling? In other words, say if two identical dryers were loaded with identical clothing that is not damaged intrinsically by high heat...we'll say cotton jeans, slacks, T-shirts, or something else like underwear maybe. Dryer 1 is set for a long dry time and low heat, while dryer 2 is set to high heat with a short dry time. With all other factors being equal ( IE washing cycle, detergent, and machine the same, as as well as wear & tear the clothes are exposed to on the wearer) which load of clothes will sustain less wear?