How to use fire blanket? 1.Take out the fire blanket. 2.Completely cover the source of the fire. 3. Use the fire blanket to protect others as they leave. What is fire blanket? The fire blanket is woven by glass fiber. When the fire blanket is placed over a burning object, it deprives the fire of oxygen, causing it to be extinguished. This achieves the purpose of isolating the fire.