Expert: John Locke - 11/25/2008

Question
someone told me that humans can just be sitting around minding their own business when they can just catch on fire and burn alive at any moment and anytime?

Will I spontaneously combust into flames? or is that an urban myth?

"incidents of SHC have been reported where the victim was in contact with flammable material, but only the individual themselves burned without igniting anything else"

Answer
Thanks for using AllExperts.

I'm not the first person to have addressed this question, so I will eventually direct you to some other summaries on the subject, but first let me include some of my observations. First, most cases of "spontaneous" human combustion are eventually found to have mundane explanations, usually involving individuals who fell asleep while smoking and wearing some sort of synthetic clothing--which is surprisingly flammable and not often appreciated. "True" cases of SHC, where a person simply bursts into flames without any precipitating factor, are very rare--even within the paranormal literature--and most skeptical investigators doubt that these ever happen at all. So to answer your question, will you spontaneously burst into flames? No. SHC, as described to you in the first part of your question, is indeed an urban myth.

Second, we tend to assume that if an individual has been consumed by fire, that fire should have destroyed surrounding structures and spread from its point of origin. In fact, that's simply not the case; fires can smolder at temperatures high enough to destroy adjacent objects without spreading to other, further structures. This is particularly true if the combustion occurs in an enclosed space, where oxygen could be consumed quickly. Many account of SHC victims described the fire as occurring in a bedroom or other small, enclosed space. This addresses the point, sometimes raised by proponents of a paranormal explanations for SHC, that an individual combusts without setting fire to the things around them. Make sense?

One of the explanations proffered to account for SHC is something called the "wick effect," in which fat from an individual who is burning may melt and be consumed, providing fuel for combustion without causing the fire to spread. This is not an unreasonable theory, given that many supposed victims of SHC were obese and found in enclosed spaces--again, exactly the kinds of conditions that favor slow-burning, lower-temperature fires that could destroy a human body without causing the fire to spread.

As promised, I'm going to direct you to some other explanations and accounts of SHC. You'll probably notice that these are all skeptical investigations of the subject, and for good reason--SHC, while very weird, can be explained with familiar and real-world factors. I wouldn't worry about it too much.   

http://www.straightdope.com/columns/read/190/do-people-really-die-from-spontaneo...

http://skepdic.com/shc.html

http://www.csicop.org/si/9611/shc.html

http://news.bbc.co.uk/1/hi/uk/158853.stm

http://www.sandiegoreader.com/news/2005/dec/15/light-my-fire/ (This is the shortest and most decisive of all the above links. Read this one for a real quick summary on what SHC really is).