Spontaneous combustion
Spontaneous combustion can occur as follows: The body can act as an capacitor and an electrical charge can be stored in the body. The more accidic the body fluids become the better electrical conductor the body fluids become, thus with a fairly dry skin the higher the electrical resistance and thus ad to the higher electrical charge stored in the body. Ad to this, poor digestion in your stomach enhances gas forming (Bloating). This high electrical charge can ignite the gasses wich can set you allight.
As a matter of interest if you get heartburn the first thing that are described is an antacid to dilute your stomach acids. In doing this your food rots in your stomach and cannot be digested thus as already stated above bloating occurs. My contravercial statement: strengthen your stomach acids by drinking say a teaspoon of vinigar ( Not apple cider vinigar) find your happy medium that will suffice for you. Doing this your food starts to digest and your heartburn subsides. This will not be easily accepted medically but believe me it is effective.