What term describes the phenomenon where gases form in layers according to temperature?

The phenomenon where gases form in layers according to temperature is known as thermal layering. This process occurs because warmer gases are less dense and rise above cooler, denser gases. In a fire scenario, this layering can greatly influence smoke movement, heat distribution, and fire behavior within a structure. Understanding thermal layering is crucial for firefighters, as it affects how they approach a fire for protection and ventilation.

The other terms relate to distinct fire behaviors; backdraft involves a rapid explosion of fire due to the introduction of oxygen, flashover refers to the quick ignition of all combustible materials in a space due to intense heat, and rollover describes the ignition of gas or smoke layers that are heated but not yet in flame. Each of these fire behaviors has different implications and tactics associated with them, separate from the concept of thermal layering.