It would be hard to call yourself a survivalist if you don’t know lifesaving CPR. That’s because if someone suffers cardiac arrest and you don’t know what to do, chances are, he or she will die within ten minutes if help doesn’t arrive, according to this infographic from carrington.edu. If you’re in a situation where you can call an ambulance, the victim’s chances of survival are better, but still not as good as if you or someone nearby knows CPR.

But what if you can’t call an ambulance or what if there is no ambulance service to begin with? If you know CPR, even just hands-on CPR, then the victim’s chances of survival are doubled or even tripled when you can keep them alive before transporting them to the nearest medical facility.

With 400,000 cardiac arrests occurring every year in the United States outside of hospitals, the chances of encountering a situation where lifesaving CPR is needed is more common than you may think. But you have to act quickly by assessing the situation. First, check to see if the victim is responsive and breathing by tapping his or her shoulder and asking if they’re okay. If he or she is unresponsive, you can call for help if others are nearby. Someone should call 911. And then life-saving CPR should be performed immediately.

To perform hands-only CPR, also referred to as “compression-only” CPR, you press down on the chest deeply—about 2 inches—100 times per minute. According to The Good Survivalist, a medical reviewer has recommended singing the song “Stayin’ Alive” by the BeeGees or “Another One Bites the Dust” by Queen to keep the tempo going. This type of CPR can be performed on anyone except newborn babies.

So that you know what to do in a life-and-death situation where a person, newborn, or animal has stopped breathing, it’s important to take a local CPR class. These classes, often given freely or for a nominal price, can be located in community centers, medical centers, fire stations, and police stations, for example.