An extinguisher is a device designed to put out fires quickly and safely. The most common type is a fire extinguisher: a metal cylinder filled with special chemicals that you spray onto flames to smother them. Fire extinguishers work by removing one of the three things fire needs to burn: oxygen, heat, or fuel.

You've probably seen red fire extinguishers hanging on walls in your school hallways or in your kitchen at home. Different types exist for different kinds of fires. A kitchen fire caused by burning oil needs a different extinguisher than an electrical fire in a computer lab. That's why fire extinguishers have labels showing which types of fires they can handle.

Using a fire extinguisher follows a simple pattern called PASS: Pull the pin, Aim at the base of the fire, Squeeze the handle, and Sweep side to side. Extinguishers are meant for small fires; if a fire is large or spreading quickly, people should get out and call emergency services right away.