Spontaneous human combustion is probably the most controversial natural phenomenon. Spontaneous combustion has been known to occur in other animals and such incidents have been observed and recorded.
Spontaneous combustion is defined as the burning of the human body without an external source of ignition, in other words, you explode for no reason whatsoever.
Evidence for this strange occurrence includes shrunken organs of the human body with clothing still attached, and several theories have been created. One theory is the “wick effect,” which states that your clothing can absorb melted human fats and thus can act like the wick of a candle. Scary, huh?