During a fire, what does the term "flashover" refer to?

"Flashover" refers to the rapid transition of a fire from the pre-flashover stage, where it is characterized by localized flames and heat, to a fully developed fire in which virtually all combustible materials in the room ignite almost simultaneously. This phenomenon occurs due to the intense heat generated by the fire, which causes all surfaces to reach their ignition temperatures.

Understanding flashover is crucial for firefighters and facility fire brigade members because it presents a significant risk, often resulting in the fire intensifying very quickly, making conditions extremely hazardous. Identifying the signs of an impending flashover, such as rapid temperature increases, heavy smoke buildup, and increased electrical load on wiring, is essential for safety and effective firefighting strategy. The other options do not capture this critical phase in the fire life cycle, as they either refer to points before ignition or after flames have been extinguished.