Fire behavior indicators are composed of which elements?

• A. Smoke/air flow, heat and flame
• B. Water pressure
• C. Building age
• D. Thermal imaging

Answer: (A)

Fire behavior indicators are the signs you read to gauge how a fire is developing. The three elements are smoke/air flow, heat, and flame. Smoke/air flow tells you how fire gases are moving and where openings are feeding or exhausting; trends like increasing velocity, thicker smoke, or smoke pushing out of openings signal intensified fire growth or ventilation-driven changes. Heat reflects the temperature rise in the space, indicating higher fire intensity and the potential for flashover if heat concentrates. Visible flames show active combustion, revealing fuel availability, ventilation status, and the current energy release of the fire. Together, these indicators guide tactics and safety decisions. Water pressure, building age, and thermal imaging are not part of the indicators themselves: water pressure relates to suppression, building age doesn’t describe current fire behavior, and thermal imaging is a tool that helps reveal heat and flames rather than being an indicator on its own.