Can humans spontaneously burst into flames?

Spontaneous Human Combustion

some have claimed that people can suddenly and inexplicably explode into a ball of fire. The phenomenon is called spontaneous human combustion (SHC).

In December 1966, the body of 92-year-old Dr. J. Irvin­g Bentley was discovered in his Pennsylvania home by a meter reader. Actually, only part of Dr. Bentley's leg and slippered foot were found. The rest of his body had been burned to ashes. A hole in the bathroom floor was the only evidence of the fire that had killed him; the rest of the house remained perfectly intact.

How could a man catch fire with no apparent source of a spark or flame and then burn so completely without igniting anything around him? Dr. Bentley's case and several hundred others like it have been labelled "spontaneous human combustion" (SHC). Although he and other victims of the phenomenon burned almost completely, their surroundings, and even sometimes their clothes, remained virtually untouched.