How is it possible for a corpse to be warm hours after death?

Answer 1

Impossible? Not necessarily. The decomposition chemistry that happens after death will increase the body temperature slightly. This increases also comes with various gas creation due to the nature of decomposition. I would not consider it "warm", but certainly warmer than tissue not exposed to degeneration.

Answer 2

Environmental factors can affect the rate of temperature loss to a corpse. The normal temperature for a body is 98.6 degrees. Now lets say the house temperature is 80 degrees and stays at 80 degrees. The corpses temperature would decrease slower, whereas in a cooler or colder environment it would decrease faster. In a garage in Phoenix, Az. where the temperature outside is 110 degrees the corpse temperature may rise. Forensic science and Medical Examiners use a lot of formulas to determine the time of death.