After professional football player Damar Hamlin suffered cardiac arrest during a game on national television Monday, experts are talking about the importance of knowing cardiopulmonary resuscitation, or CPR. 

CPR is a life-saving skill, used when someone is unconscious and in cardiac arrest. Jordan Meeks, a pediatric wellness specialist at OSF HealthCare, says it’s a critical skill for young people to learn.

If someone is having a cardiac event, she says the first thing to do is call 9-1-1. If you’re by yourself, put the phone on speaker while you help the ailing person. Get over the person, interlink your fingers and press hard in the middle of the chest over and over.