It's so long since most people did a first aid course that they usually have only a vague recollection of what they learned. But in an emergency there's virtually no time to think: you have to act. The chances of surviving a cardiac arrest dwindle every minute without basic life support.
Cardiac arrest can occur very suddenly, often following a heart attack or cardiac arrhythmia. The warning signs are shortage of breath, a cold sweat, or serious chest pains, often spreading to the arms, upper abdomen, back or neck. The person affected will often fall over, or collapse if they're sitting. They're no longer responsive and they're not breathing normally.
For a number of years now, AEDs have been freely accessible in public places in Switzerland, for example in pharmacies, medical practices, schools, shopping centres and office buildings. They're designed to be used without training or prior knowledge. As soon as you switch the AED on, it talks to you and gives you step-by-step instructions on what to do. The AED can bridge the gap before the emergency services arrive on the scene.