Spontaneous combustion
https://en.wikipedia.org/wiki/Spontaneous_human_combustion
“Spontaneous human combustion” refers to the death from a fire originating without an apparent external source of ignition; the fire is believed to start within the body of the victim. This idea, and the term “spontaneous human combustion”, were both first proposed in 1746 by Paul Rolli in an article published in the Philosophical Transactions concerning the mysterious death of Countess Cornelia Zangheri Bandi.[1] Writing in The British Medical Journal in 1938, coroner Gavin Thurston describes the phenomenon as having “apparently attracted the attention not only of the medical profession but of the laity one hundred years ago” (referring to a fictional account published in 1834 in the Frederick Marryat cycle).[2] In his 1995 book Ablaze!, Larry E. Arnold wrote that there had been about 200 cited reports of spontaneous human combustion worldwide over a period of around 300 years.[3]
That is one reason pro sound crews always bring a fire extinguisher. Sometimes you have to save the drummer.