What is the phenomenon called when all exposed surfaces within a compartment ignite at once?

The phenomenon where all exposed surfaces within a compartment ignite simultaneously is known as flashover. This critical event typically occurs in a fully involved room when the temperature increases to the point where the combustible materials reach their ignition temperature, resulting in a rapid fire spread throughout the space. Flashover can occur very quickly, often within a matter of seconds, following a buildup of heat and smoke in a confined space.

Understanding flashover is vital for firefighting strategies, as it greatly increases the danger to both occupants and firefighters. Recognizing signs of an impending flashover, such as high heat and voluminous smoke, can provide essential information for making tactical decisions while combating a fire in building structures.