Define the term "flashover" in fire dynamics.

Flashover refers to a critical moment in fire dynamics where a room or enclosed space reaches a temperature sufficient for the ignition of all the combustible materials present, leading to a rapid spread of fire throughout that space. This phenomenon occurs when the heat from the flames causes all the surfaces and gases within the environment to ignite almost simultaneously, resulting in an explosive increase in the fire's intensity and spreading velocity.

This definition highlights the significance of temperature and the availability of combustible materials, as these are key factors that contribute to the rapid transition from a localized fire to a fully developed fire that can engulf an entire area. Understanding flashover is essential for firefighters and safety personnel, as it has critical implications for fire behavior, safety strategies, and effective response measures during firefighting operations.