What describes the phenomenon of the doughnut-shaped pattern in fire investigations?

The phenomenon of the doughnut-shaped pattern in fire investigations is accurately described by the cooling of the center of the application area while flames burn the perimeter. This pattern typically occurs when a fire starts at a certain point and then spreads outward, causing the area around the center to be exposed to higher heat and thus burn more intensely. Conversely, the center, which may be sheltered from direct flames, cools down as the fire spreads outward. This results in a distinct shape resembling a doughnut, where the inner section is cooler or less burned compared to the outer edges.

In the context of fire investigations, recognizing this pattern can be critical in determining the origin and dynamics of the fire, as it provides clues about how the fire spread and the conditions present during the incident. Proper interpretation of such patterns can assist investigators in reconstructing the sequence of events that led to the fire.