Use an AED when a person suddenly collapses, is unresponsive, and is not breathing normally. Time is critical; using an AED alongside CPR within the first few minutes significantly increases the chance of survival.

When NOT to Use an AED

• Conscious Individuals: Never use an AED on someone who is responsive, breathing normally, or has a clear pulse.
• Water Hazards: Do not use the device if the victim is submerged in water or lying in a large, conductive puddle.
• Moving Vehicles: Do not apply it inside a moving ambulance or car, as the vibrations can interfere with the machine's analysis.
• DNR Orders: Honour valid Do Not Resuscitate (DNR) instructions if you know they apply to the victim.