Spontaneous Human Combustion is when a human body is found reduced to ashes with no apparent source of ignition. Often times, the middle of the body will be the most burnt, while the head, arms, and legs will be more intact.
Cases have been reported since the 17th century. Often times, the victim dies of natural causes, but the burning occurs post-mortem. Two common factors among SHC cases are obesity and alcoholism. Excessive alcohol consumption can lead up to the buildup of acetone in the body, which would make you more prone to catching on fire.
One mysterious part about Spontaneous Combustion cases is the fact that the bodies are almost always reduced to ash, yet there is often no damage to the furniture around them. This is strange because the human body needs to be burned at a temperature of 3000 degrees in order to be turned to ash. At that high of a temperature, you’d think that the furniture around them would also catch on fire.