It's a nagging worry that constantly loiters in the recesses of the mind: "Will today be that day I spontaneously combust?"
I'm hard-pressed to think of a worse way to go. One day, you might be walking down the street, suffering from a faint tinge of indigestion, when suddenly, poof; you're up in flames. Or perhaps you might be slouched in an armchair, lightly dozing and watching football, when the temperature of the living room unexpectedly jumps a few hundred degrees. Nope, that's not the furnace malfunctioning; it's just your torso... on fire.
The only consolation of combustion is this: the unadulterated pain would rapidly trigger the body's vasovagal reflex, inducing welcome, numbing unconsciousness in a matter of seconds.
There are no credible eyewitness accounts of spontaneous combustion,
but the aftermath is described like so: Remains are found in the form of an ash heap, but the legs remain relatively unscathed. Furthermore, the
surroundings show minimal signs of fire damage. Only the deceased seems
to have burned.
Fewer than 150 cases of spontaneous human combustion have been reported over the last two thousand years. The rareness has rightfully engendered skepticism as to whether the condition truly exists. After all, the human body is approximately sixty percent water. It's simply not flammable.
Yet the unexplained cases still beg an explanation.
"The main theory was always alcoholism," microbiologist Brian Ford told BBC Radio. "People always said that people would drink too much alcohol. Their tissues would become soaked in alcohol, and they'd become inflammable."
This false belief has persisted despite the work of noted German chemist J. von Leibig, who, in 1851, pointed out that anatomical specimens preserved in 70% ethanol don't catch fire. Leibig went even further to substantiate the point. In tests that probably wouldn't pass ethics reviews today, he injected rats with ethanol over prolonged periods and tried to set them on fire. It didn't work.
Seeking an answer to the combustion conundrum, Ford recently searched through the well-documented cases of spontaneous human combustion and realized one commonality: all of the victims seemed to have been unwell. When we're sick, or the body is severely stressed, blood glycogen -- a carbohydrate that our muscles use for fuel -- can become easily depleted. This leads to fat molecules getting broken down and used as energy, instead. If the process is accompanied by cellular starvation, which can occur during chronic illness or even during a strenuous gym workout, acetone can be produced.
It's acetone that Ford theorizes may be the culprit for spontaneous human combustion. Not only is it highly flammable, it can also easily mix with water and lipids, and can thus permeate throughout the body.
To test his theory, Ford constructed 1/12 scale replicas of humans using pig tissue previously soaked in acetone. When set alight, the test dummies blazed magnificently, leaving, as Ford described in NewScientist, "a pile of smoking cinders with protruding limbs," almost identical to the documented human cases of spontaneous combustion.
Ford openly acknowledges that his experiments are by no means conclusive, though they do present the most plausible explanation yet.
Don't fret; it's extremely unlikely (almost impossible) that a human will simply catch fire without an external catalyst of some sort. Our bodies aren't hazardous chemical factories on the brink of disaster.
But just in case these musings don't assuage your fear of bursting into flames, can you take a couple simple steps to further mitigate the meager chances that you'll spontaneously combust:
1. Avoid activities and diets which promote ketosis, the bodily state where levels of ketones -- like acetone -- are elevated. These include alcoholism, starvation, and diets based on low-carbohydrate and high fat/protein intake.
2. Avoid potentially dangerous sources of flame or high temperature, especially when drowsy. And don't smoke.
(Image: Attempted Combustion via Shutterstock)