Hazards from fire include which of the following sets?

• A. Temperature
• B. Heat flux
• C. Oxygen depletion and fire gases
• D. Temperature, Heat flux, Oxygen depletion and fire gases

Answer: (D)

When a fire occurs, hazards come from several interacting factors in the environment, not just one. High temperatures and the heat already present on surfaces and in the flame can cause burns. Heat flux describes how rapidly heat is transferred to you or objects at a distance; even without touching the flame, intense radiant heat can injure skin, ignite materials, or cause unconsciousness. As the fire consumes oxygen, the surrounding air becomes depleted of oxygen, which can lead to dizziness, fainting, or asphyxiation in enclosed spaces. The fire also releases gases from combustion—smoke and toxic gases like carbon monoxide and hydrogen cyanide—that impair breathing, reduce visibility, and can be deadly.

All four hazards—temperature, heat flux, oxygen depletion, and fire gases—can occur together in a fire, so the set that includes every one of them represents the full range of fire hazards.