Gasoline vapor auto ignites without a spark at 495F.
If the cigarette "cherry" was 495 it would auto ignite.
And before this goes all 2005 internet and someone claims that fuel, oxygen and a spark are required for every fire, just remember how a diesel engine works.
But the better logic is even if it isnt likely to cause a fire it causes no good so why the fawk do it?
I want kill the fawker, without having met him, for smoking in public. Im pretty tolerant but Id rather be spit on than have smoke blown in my face.