Question

In stretching a rubber band why does it feel warm?

Answer 1

The rubber band actually expands when it gets colder! This seems counter intuitive because most materials expand when they are heated and contract when they get cold. This occurs because of the unusual polymer structure of rubber. ... When the chains cool down, they relax and stretch out, causing the material to expand.

Answer 2

I always used to wonder why this happens.. when one stretches a rubber band to nearly it snapping point holding it close to your skin - preferably cheek(helps feel the heat), it emits heat. While releasing the stretched rubber band holding it close to the skin produces a cooling effect on the skin.