The rubber band experiment demonstrates entropic force and a refrigeration cycle using a simple rubber band. The rubber band experiment is performed by sensing the temperature of a rubber band as it is stretched, and then released. The rubber band first heats up as its stretched, then allowed to equilibrate back to room temperature. The rubber band cools below room temperature when the tension is released, the effect is large enough to be noticed by touch. The rubber band experiment is often used as a simple example when explaining entropy and energy in high school physics classes.