Hi, Aaronjm. Welcome to the cut and thrust of Focus Forums.
M Paul Lloyd wrote:From what I know of these cases it seems most likely that some external ignition source, cigarette, electric/gas fire triggers a chain reaction known as the wick effect rather than the body itself simply bursting into flames.
As far as I have been able to establish, all well documented cases of spontaneous human combustion have had an external heat source and fit in with the wick effect, which has been tested experimentally and shown to be quite real.
aaronjm1986 wrote:Could it theoretically be caused by a major malfunction in the hypothalmus, the brain's centre that controlls our body temperature
A malfunction in thermoregulation could result in an elevated body temperature. However, anything above 42°C is potentially lethal and certainly by 45°C you're toast, at which point the hypothalamus and all parts endocrine, will cease to function, well short of a potential ignition temperature. So I would say theoretically, and practically, the answer is almost certainly, no.
Of course, there may be other explanations.
Knowledge comes, but wisdom lingers.