Backdraft indicators include which of the following heat-related signs?

• A. Building Indicators
• B. Smoke Indicators
• C. Airflow indicators
• D. Heat indicators

Answer: (D)

Backdraft happens when a fire burns in a closed or poorly ventilated space, causing hot, fuel-rich gases to build up and heat to rise. The most telling signs are heat-related: the space feels intensely hot at the entry, surfaces such as walls or doors radiate or glow with heat, and metal objects like door handles or hinges can become very hot to the touch. This extreme heat buildup is what makes the sudden introduction of air so dangerous, because it can ignite the accumulated gases in a flash. While other cues like how the smoke or the building appears or how air seems to move can appear in some cases, the heat indicators directly reflect the dangerous temperature conditions that lead to a backdraft.