How is a pencil eraser able to get hot enough to burn when rubbed against skin ?

Why is it able to produce so much heat when rubbed on the skin but not when against paper?|||Paper%26#039;s flash point is 451掳 F, and it will not ignite without a spark or source of ignition until it reaches this temperature. Skin can burn at much lower temperatures.|||The eraser gets heated because the work done overcoming friction is turned into heat. This heat is generated only at the rubbing surface and,rubber being a poor heat conductor,the temperature of a quite thin layer can get pretty high.Now think about this thin layer being rubbed hard on paper! It gets rubbed off the eraser as gunge all over the place;especialy since this hot thin layer is weaker than cold rubber.I%26#039;m not sure what your asking about the effect on skin but it seems to me that skin would never be strong enough to remove the hot layer of rubber so it would get progressively hotter until the water in the outer layers of you skin boiled.You cant get any hotter so long as you still have water in your skin.If you go on torturing yourself beyond this point you could become a fire work so invite a few friends around and kiss mum and dad GOODBYE.|||Because paper is smooth so the eraser doesn%26#039;t have as much friction that produces the heat! The skin isn%26#039;t as smooth and increases the friction and heat!|||Friction causes the heat. When the eraser is rubbed against skin, it heats up and will burn you. There does not appear to be enought friction between the paper and the eraser to cause it to heat up much.