Iona has a number of automated external defibrillators (AEDs), located across the island, for use by members of the general public. An AED is a portable device that checks the heart rhythm and can send an electric shock to the heart to try to restore a normal rhythm. AEDs are used to treat sudden cardiac arrest (a condition in which the heart suddenly and unexpectedly stops beating). If you come across someone suffering a sudden cardiac arrest, using an AED could save their life.
Information about their use can be found here: https://www.bhf.org.uk/heart-health/nation-of-lifesavers/about-defibrillators.
You can view the poster with defibrillator locations on Iona here in pdf format.