Try it with a rubber band. Stretch a rubber band and quickly hold it against your cheek. It feels warmer. Usually when things expand, a gas or liquid, for example, they become cooler.
When a liquid (or gas) expands, it takes the energy required for expansion from the liquid itself. So the liquid becomes cooler.
When a rubber band is stretched, it is not using up its internal energy. Energy is being supplied to it from the outside (by the one who is stretching it). So its internal energy increases and its temperature rises, making it slightly warmer to the touch.
Picture Credit : Google
