You don't need to  know how to perform mouth-to-mouth cardiopulmonary resuscitation (CPR) to save the life of someone in cardiac arrest. You can use hands-only CPR.

Hands-only CPR consists of just two steps:

1. Call 911 if you see a teen or an adult collapse and they're not responsive when you ask them if they're okay.

2. Push hard and fast in the center of the person's chest. Use the beat of the disco classic "Stayin' Alive" to guide your compressions. No mouth-to-mouth breathing is required.

According to the American Heart Association (AHA), the vast majority of cardiac arrests take place at home or in a nonhospital public place. Most people who haven't learned CPR feel helpless to act in that situation. Yet when a person has a cardiac arrest, their survival depends on how quickly someone performs CPR.

That's where hands-only CPR comes in. It has been shown to be as effective as full CPR during the first few minutes of a cardiac arrest.