How would you remove the heat from a fire?

• A. You cool the fire (for example with a water glycol extinguisher, or non flammable liquids)
• B. You cut off the fuel supply
• C. You smother the fire
• D. You starve the fire

Answer: (A)

Removing heat stops many fires because the flame needs heat to keep the fuel at its ignition temperature and to drive the chemical reaction. Cooling the fuel and surrounding environment lowers the temperature below what’s required for combustion, so the flame can no longer sustain itself.

Water is especially effective for this because it has a high specific heat capacity and a very high heat of vaporization. When water absorbs heat, it first warms up and then boils away into steam, taking a large amount of energy with it. That energy absorption quickly lowers the flame temperature and can extinguish the fire.

Other choices focus on removing fuel or excluding oxygen. While starving the fuel or smothering the fire can also work, they don’t directly remove heat, which is what this question emphasizes.