If you fall and skid to a stop on a carpeted floor, you can get a rug burn. Much of this discomfort comes from abrasion, but there can also be a real burn where the skin was too hot. How does this happen?

When you run, your body has a kinetic energy and when you fall while running, the friction between the carpet and your foot, transforms the kinetic energy into thermal energy or heat energy. This can even cause, real burn if the skin were too hot.