What to do if you witness a cardiac arrest
Start CPR and ring 999 if you witness a person in cardiac arrest
The ambulance operators will direct you to the defibrillator if there is one nearby. They will also provide you with a code, if required, to unlock the cabinet. The defibrillator will talk you through what to do until the paramedics arrive.
A person's chances of surviving a cardiac arrest can be tripled if defibrillation is done early enough.