Wouldn't it be amazing, if you had superpowers? Specifically, wouldn't it be amazing if your superpower were the ability to make fire? Think of all the fun stuff you could do; you could fly and burn stuff and stuff. Wouldn't that be amazing? No! It would make you dead!
There's a theory, quite possibly compounded by 'fictional' characters like the Human Torch, that if one had the ability to generate flame, then one must be immune to its effects. Inflammable, if you will. Except that inflammable actually means flammable! In all likelihood, if you were able to make fire with your body, you wouldn't look like this:
So much as this:
And that, it is theorised, by me, is the cause of so-called Spontaneous Human Combustion: bad superpowers.
There are other things that people say is causing SHC, that are patently ridiculous, and I will burn down these straw men now.
This is because of Dickens and Bleak House, where a drunkard combusts all over the place. It does make some kind of sense, as alcohol is more likely to explode than, say, a normal non-drunk human person. But this can be disproved by virtue of the fact that certain Irish countries I could mention have yet to be entirely engulfed by a sea of giant, boozy fireballs.
2. Cigarettes, matches, lighters, etc.
Most SHC cases do occur at parties, pubs, houses: the kinds of place where, historically, people could smoke, and so some naysayers have put SHC down to accidental cigarette droppage/matches horseplay. Which is of course ridiculous. If someone had set themselves/someone else on fire with a match or cigarette, surely they would immediately jump to inform the relevant authorities? This theory assumes that we live in a world full of murderous liar types who like setting people on fire, and I think we can all agree that that's a world we'd rather not live in.
I'm sure some instances of SHC occurring since the smoking ban would further help to disprove this theory, but I have yet to find any. Though they are likely to have occurred, a lot.
This one is completely cock-a-hoop. They say that the methane in our stomachs could maybe create enough heat, and be combustible enough, to make us blow up from the inside.
a) That's what farting is for!
and b) What about the pigs? And the cows? They make more methane than us, right? And you don't hear of any evidence of cows spontaneously combusting right there in the middle of the fields, right?
Unless... no, that couldn't be it... could it?