According to the American Heart Association, hands-only CPR has been shown to be as effective as conventional CPR when cardiac arrest happens at home, work or elsewhere in public. More simple than conventional CPR, the hands-only technique may help bystanders overcome their panic and hesitation to act.

Here's what to do if you see an adult or teenager suddenly collapse:

— Call 911

— Push hard and fast in the center of the chest to the beat of the disco song "Stayin' Alive."

— Push at a rate of 100 to 120 compression per minute, at a depth of 2 to 2.5 inches, until medics or someone with an automated external defibrillator (AED) arrives or until the person becomes responsive.

Here's when conventional CPR — compressions and mouth-to-mouth breathing — is recommended:

— When an infant or child collapses.

— When the cause of the collapse is drowning, drug overdose or breathing problems.

— When someone is found already unresponsive and not breathing normally.

To take a CPR class, call 1-877-242-4277 or go to cpr.heart.org to learn about available courses where you live.

— Source: American Heart Association