I remember reading a detailed post from a person who described a TV show that highlighted a case where a man's digestive proteins drew out too much heat. His body hadburnt to nothing but minerals within less than 15 seconds. The poster said that the woman had left the room, and the fire alarm went off. She came back in 15 seconds but he was already incinerated to a 2d shilluette. This meant his bodytemp reached approx. one hundred thousand degrees C.