Have you ever heard of a backdraught? This is what happens when oxygen quickly enters an environment where there isn't much of the gas already present. One example would be a window breaking during a house fire and letting in lots of fresh air. This quick video shows what firefighters can face in these situations - a fireball that is extremely dangerous 🔥 It's why we train so hard to be prepared! This was filmed at one such session at our Training Centre in Chorley. | Lancashire Fire and Rescue