Administering CPR can more than double a person’s chances of survival after cardiac arrest.

When performing CPR, the person should be lying flat on their back. Then, put one hand over the other in the middle of their chest and start doing compressions 100 to 120 times per minute, Dr. Tamanna Singh, a cardiologist with Cleveland Clinic said.

It is also important to know how to use an AED. However, those devices can usually talk you through everything themselves.

The device will identify whether the rhythm the patient is one where an electrical shock is one that can actually revive them or make them responsive again.

AEDs can be found in many public places like schools, stores and offices.