This phenomenon of sudden and total combustion in an enclosed space is known and feared by municipal firefighters. They call it “flashover,” a reference to the flashing, or reflective nature of radiant heat, and it poses a lethal hazard for anyone inside a burning building. Because fire feeds on the gases released by heated fuel (as opposed to the fuel itself), a localized fire—like a burning sofa—will radiate heat that causes off-gassing in the fuels around it.
