In terms of fire behavior, what does the term "thermal layering" describe?

The term "thermal layering" specifically refers to the arrangement of hot and cool gases within a fire environment. As combustion occurs, heat is generated, causing the gases closest to the fire source to become very hot, while the gases further away are cooler. This results in a stratification effect, where the hottest gases rise to the top of the room or area, creating a layer of hot, buoyant gases above the cooler layers. This phenomenon can significantly influence fire behavior, including the movement of smoke and the potential for flashover, as the cooler layers may become saturated with heat, ultimately affecting how firefighters plan their approach to controlling a fire. Understanding thermal layering is crucial for fire safety and effective firefighting strategies, as it helps in predicting the behavior of smoke and heat in the environment of a fire.