Learning how to apply a tourniquet correctly can save a life by stopping or slowing bleeding until 911 emergency help arrives. Tourniquets are bands that are tied around an arm or leg when bleeding is uncontrollable due to a severe wound like a gunshot, stabbing, or heavy machinery accident.

Ideally, tourniquets should be applied by first responders who are trained in emergency first aid. But there are times when delaying is not an option, and knowing how and when to apply a tourniquet can be the difference between life and death.

This article outlines when tourniquets should (and should not) be used, as well as the proper way to apply this important first aid device.