Which paleolithic period did cave art start?

Cave art is shown to date back to around 40 thousand years ago. Evidence shows they were nor purely cosmetic/decorative. The earliest figurative paintings date back to the Aurignacian period.  

Generally spontaneous human combustion is something that still bewilders some, human combustion happens very rarely and doesn't affect the surrounding areas, so unless you want to set your self on fire, human combustion will remain spontaneous and very rare.