What is flashover in the context of fire behavior?

Flashover is defined as a sudden and rapid increase in fire intensity that occurs when the combustible materials in a room reach their ignition temperature almost simultaneously. During flashover, the heat generated by the fire causes the surfaces near the flames to reach their auto-ignition temperature, leading to a dramatic transition where all combustible materials in the area ignite.

This phenomenon can happen in just a matter of seconds and is characterized by a significant and swift increase in heat and smoke production, making it one of the most dangerous stages of a fire. Understanding flashover is crucial for firefighters, as it influences tactics and strategies for fire suppression and rescue operations.

The other options do not accurately describe flashover; they depict different aspects of fire behavior. A slow, gradual increase in fire intensity refers to a more typical growth phase of a fire. The cooling phase of a fire is a post-flashover stage where the fire is being extinguished. A method of fire extinguishment does not relate to the specific behavior of fire like flashover does. Therefore, the recognition of flashover as a sudden increase in fire intensity is vital for effective firefighting and safety.