Fire needs three things to burn: oxygen, fuel, and heat. Fuels can be wood, tinder, coal, or any other substance that will easily oxidize. Therefore, a fire can be stopped in three different ways, by removing any of the three things it needs to burn. • The fuel can be removed. If a fire burns through all of its fuel and extra nearby fuel is removed, the fire will stop burning. • The oxygen can be removed. This is called "smothering" a fire. Fires cannot burn in a vacuum or if they are covered in carbon dioxide. • The heat can be removed. The most common way to remove heat is to use water to absorb that heat, putting the fire out.