What phenomenon occurs when all surfaces and objects in a space reach their ignition temperature and flames break out nearly simultaneously?

The phenomenon described occurs during flashover. Flashover is a critical and dangerous stage in fire development where the heat generated by the fire raises the temperature of all combustible materials in the room to their ignition point almost simultaneously. This results in flames erupting throughout the space, often leading to an explosive expansion of the fire.

Flashover typically takes place when the thermal radiation from the flames heats the surrounding surfaces, accumulating enough heat energy to ignite every flammable object present in the environment at once. This rapid transition increases both the intensity and the scale of the fire dramatically, making it a significant concern for firefighters and safety personnel.

Rollover, although related to fire behavior, refers to the phenomenon where flames propagate along the ceiling level due to the accumulation of hot gases, rather than the simultaneous ignition of all surfaces. Backdraft is a different situation involving an explosive event that occurs when oxygen is reintroduced to a smoldering fire, leading to a sudden and violent rekindling. The fire triangle represents the three essential elements of fire—heat, fuel, and oxygen—but doesn’t describe the simultaneous ignition phenomenon itself.