A backdraft is a sudden and explosive ignition of gases that happens when a fire has been burning in a confined space and runs out of oxygen, then fresh air suddenly enters the area. Here’s how it happens step by step: ➡️Fire burns in an enclosed space (like a room or building). ➡️The oxygen inside gets used up, so the flames die down — but hot gases and smoke full of unburned fuel remain. ➡️When a door, window, or other opening is made, fresh air rushes in. ➡️The oxygen mixes with the hot gases