Which of the following is NOT usually considered a principal hazard?

Very dry conditions are often seen as a contributing factor to fire behavior rather than a principal hazard itself. Principal hazards typically refer to immediate threats that could lead to injury or fatality during an incident, such as physical exertion, rapid fire spread, and hazardous energy.

Physical exertion is a significant hazard, especially in firefighting situations where personnel may face physical demands that can lead to exhaustion or injury. Rapid fire spread poses an immediate danger as it can quickly change the dynamics of a fire scene, making it more difficult for firefighters to maneuver and respond effectively. Hazardous energy, which includes factors like electrical hazards or stored energy in equipment, can also present a direct danger to safety personnel on site.

While very dry conditions can certainly influence the behavior and intensity of fire, they do not represent a direct or immediate hazard in the same way that the other factors do during operations. This distinction helps identify the specific threats that must be managed proactively in emergency response situations.