What is a risk of uncontrolled ventilation during overhaul?

• A. It helps to cool the fire rapidly, reducing damage.
• B. It prevents embers from reigniting.
• C. It can spread heat or embers and worsen the fire or rekindle hidden hotspots.
• D. It has no impact on fire progression.

Answer: (C)

Uncontrolled ventilation during overhaul introduces new air into spaces that may still house hidden heat or embers. That added oxygen can wake up smoldering pockets in walls, ceilings, or voids, causing rekindling or spreading heat and embers to adjacent areas. This can worsen the fire or re-ignite hotspots that seemed extinguished, prolonging the work and increasing risk to firefighters. So the main risk is that it disperses heat or embers and can reignite hidden fires.