What is a key safety practice regarding doors on entry?

• A. Keep doors open when not actively advancing
• B. Keep doors closed while actively advancing to protect heat
• C. Fire attack requires doors to be kept closed to maintain compartmentalization and reduce heat transfer
• D. Doors should be removed for visibility

Answer: (C)

Keeping doors closed as you enter a fire area is essential because doors are barriers that control how heat, smoke, and fire move through a building. When doors stay shut, they preserve compartmentalization, which slows the spread of heat and reduces the rate at which adjacent spaces become involved. That containment buys valuable time for firefighters to locate victims, advance toward the fire, and set up coordinated ventilation and attack lines without being overwhelmed by rapidly increasing temperatures and smoky conditions.

Opening a door can create a new ventilation path, feeding the fire with oxygen and pushing heat and smoke into areas that crews have yet to reach. This can dramatically raise the danger, compromise visibility, and impair egress routes. So the safest, most effective approach is to keep doors closed during fire attack unless ventilation or other tactical actions require opening them, and any door opening should be directed and coordinated by the incident command.