Actually performing CPR can be daunting if you don't actually know how. Here are the steps to follow, recommended by Save a Life Scotland.
How to do CPR
1. Put your hand in the middle of their chest
2. Interlock your fingers, hands one over the other like this
3. Keep your arms straight with your shoulders over your hands.
4. With your body weight, push down as hard as you can and then lift up. Press down 2 times every second. Or to the rhythm of the song “Staying Alive”.
5. Keep going until the ambulance or other help arrives. If you have another person with you, it's a good idea to get them to take over if you get tired.