John is riding a ski lift to the top of Wildcat Mountain. He removes his gloves and rapidly rubs his hands together to warm them up. What happens when John rubs his hands?

Well obviously his hands warm up. But this is because of the friction of his hands rubbing together. This energy is called Kinetic (not friction energy). All in all when you rub your hands together to warm them thermal and kinetic energy happens.

It's friction or kinetic energy and his hands warm up