I was reading the Feynman lectures and in one of the chapters on thermodynamics it is stated that stretching a rubber band makes its temperature rise. I feel like I understand the thermodynamics of the rubber band and yet this statement is puzzling me. I believe that when you stretch a rubber band, it will release heat. This is in agreement with the hot sensation that you feel if you were to put the rubber band to your upper lip (this is a common experiment). Wouldn't this release of heat be consistent with a decrease in temperature, not an increase?