What does the term "flashover" refer to in firefighting?

The term "flashover" refers to a rapid spread of fire that occurs when the temperature in a compartment or area becomes high enough to ignite all combustible materials simultaneously. This phenomenon typically happens when the heat and gases produced by a developing fire reach a critical point, leading to an explosive transition from a localized fire to an all-encompassing blaze.

Understanding flashover is crucial for firefighters, as it signifies a major increase in fire intensity and presents significant risks. Recognizing the signs of an impending flashover can help firefighters take appropriate action to protect themselves and execute their operations more effectively. This is why "rapid spread of fire" is the correct characterization of flashover, as it highlights the sudden and dangerous acceleration of fire behavior in a confined space.