What term describes the spontaneous ignition of hot gases at the upper level of a room?

The term that describes the spontaneous ignition of hot gases at the upper level of a room is rollover. Rollover occurs when heat and gases collect at the ceiling level, and once they reach a certain temperature, those gases ignite, creating flames that can roll across the ceiling. This phenomenon is significant in firefighting, as it can indicate that the fire is growing and becoming more intense.

Understanding rollover is crucial for firefighters because it helps them identify the potential for rapid fire spread and the need for immediate action to manage the situation safely. It can also serve as a warning sign for firefighters to be cautious when entering a space, as the presence of rollover can indicate that conditions are deteriorating quickly.