What does thermal layering refer to in fire behavior?

Thermal layering refers to the phenomenon where heat rises due to its lower density compared to cooler air. In the context of fire behavior, this leads to the establishment of distinct layers of temperature within a burning environment. Warm air, heated by the fire, rises and creates a hotter layer above, while cooler air stays closer to the ground. This temperature stratification affects the behavior of smoke and heat within a structure, including the potential for flashover, a critical concern for firefighters.

Understanding thermal layering is essential for assessing fire behavior, predicting fire spread, and developing strategies for ventilation and firefighting. It allows firefighters to anticipate places where heat and smoke may accumulate, helping them make informed decisions while approaching a fire scene. Recognizing the significance of thermal layering assists in ensuring the safety and effectiveness of firefighting operations.