During which phase does a fire experience a rapid increase in temperature and intensity?

The phase in which a fire experiences a rapid increase in temperature and intensity is known as the free burning phase. During this stage, the fire has sufficient oxygen and combustible materials available, allowing it to reach its peak burn rate. This is characterized by a dramatic increase in fire intensity, as flames grow larger and spread more quickly, often resulting in significant heat release.

In the free burning phase, the combustion process is efficient, and the flames are typically well-ventilated, leading to higher temperatures and more violent conditions. It's crucial for firefighters to recognize when a fire has entered this phase, as it can significantly impact their tactics and approach to controlling or extinguishing the fire. Understanding the dynamics of this phase allows for better situational awareness and strategic decision-making in firefighting operations.