Which statement best describes signs of a ventilation-controlled fire?

• A. The fire produces bright, continuous flames at openings
• B. All windows remain clear and interiors cool
• C. You can't see through windows, inside surface of windows look fuzzy, interior surfaces burned, exterior doors and windows warm to touch, TIC shows residual heat on doors and walls, soot around exhaust openings, thermal column reported/not seen, witnesses claim there was lots of fire earlier but nothing showing upon your arrival
• D. Smoke is completely absent and temperatures are low

Answer: (C)

A ventilation-controlled fire means the heat release is limited by the amount of oxygen available, so you often get a hot, smoky environment with little visible flame and signs of extreme heat on surrounding surfaces.

The description in this option fits that scenario: you can’t see through the windows because thick, smoke-filled conditions dominate; interior surfaces show damage or burning from the intense hot gases; exterior doors and windows feel warm to the touch, indicating heat buildup at the openings; a thermal imaging camera shows residual heat on doors and walls, pointing to hot surfaces behind the smoke; soot around exhaust openings signals ongoing, fuel-rich combustion and deposition from the hot gases; whether a clear vertical thermal column is seen can vary, but its presence or absence doesn’t contradict the ventilation-limited condition; witnesses noting heavy fire earlier but nothing showing on arrival reflects how the fire’s growth was suppressed by lack of air, with flames suppressed until ventilation changes.

In short, these signs—heavy, smoky conditions, heat on surfaces, and heat buildup with limited visible flame—are typical indicators of a ventilation-controlled fire.