To carry out a chest compression:
- Place the heel of your hand on the breastbone at the center of the person's chest. Place your other hand on top of your first hand and interlock your fingers.
- Position yourself with your shoulders above your hands.
- Using your body weight (not just your arms), press straight down by 5 to 6cm (2 to 2.5 inches) on their chest.
- Keeping your hands on their chest, release the compression and allow the chest to return to its original position.
- Repeat these compressions at a rate of 100 to 120 times a minute until an ambulance arrives or you become exhausted.