Explain the term 'thermal layering' in fire dynamics.

Thermal layering refers to the stratification of heat within a room, which occurs due to the differences in temperature and density of the gases present. As heat rises, warmer air accumulates near the ceiling while cooler air remains closer to the floor. This phenomenon is crucial to understand in fire dynamics because it significantly influences the behavior of a fire and the smoke within an enclosed space.

When a fire occurs, the heat generated can create distinct layers of temperature, affecting how firefighters respond to the fire and how smoke spreads through the area. The higher temperatures at the ceiling can lead to rapid fire spread and subsequent flashover if these layers mix or reach a critical temperature. Understanding thermal layering helps in predicting fire behavior and implementing effective strategies for both extinguishing the fire and ensuring the safety of occupants and firefighters.