What is an AED?
An automated external defibrillator, or AED, is a compact, user-friendly device designed so that ordinary people — not just medical professionals — can help someone in cardiac arrest. It checks the heart's rhythm and, if needed, delivers an electric shock to reset it. Crucially, AEDs talk you through every step with clear voice prompts, and they will not deliver a shock unless the heart actually needs one. You cannot accidentally shock a person whose heart does not require it.
You will find AEDs mounted on walls at many pools, gyms, schools, and public buildings, usually in a bright cabinet marked with a heart-and-lightning symbol. Knowing they exist — and noticing where they are when you arrive somewhere — is the first step to using one in time.
Why drowning can stop the heart
Drowning is fundamentally an oxygen problem. When the airway and lungs fill with water, the body is starved of oxygen, and without it the heart can slow and eventually stop — a cardiac arrest caused by lack of breathing. This is different from the sudden cardiac arrest that strikes some adults, which is why the response order differs slightly. In drowning, restoring oxygen through rescue breaths and chest compressions is the top priority, and the AED is a powerful tool that supports that effort if the heart has developed a shockable rhythm.
CPR comes first — then the AED
The sequence matters. If you pull someone from the water who is unresponsive and not breathing normally:
1. Call 911 (or have someone else call) and ask them to find the nearest AED.
2. Start CPR immediately. Begin chest compressions and rescue breaths without delay. Drowning victims especially benefit from rescue breaths because the core problem is oxygen. Our CPR basics for parents and water-rescue CPR guide walk through the technique.
3. Use the AED as soon as it arrives, following its prompts, while continuing CPR between shocks and analyses.
The AED does not replace CPR — it works alongside it. Good CPR keeps oxygen moving until the AED (and paramedics) can do their part.
Using an AED on a wet person
This is the part unique to water emergencies, and it is simpler than it sounds. The concern is that water can interfere with the pads sticking and can let the shock disperse across wet skin instead of going through the heart. So before you attach the pads:
Move the person out of standing water. Get them onto a dry surface — the pool deck away from puddles, not lying in water.
Quickly dry the bare chest. Use a towel, shirt, or whatever is handy to wipe the chest where the pads go. It does not need to be perfectly dry — just not dripping.
Then place the pads as the diagram shows and let the AED analyze. Make sure no one is touching the person when it analyzes or shocks.
A small puddle nearby is not a reason to avoid using the AED — just get the person and their chest reasonably dry first. Modern AEDs are designed to be used in real-world conditions, including at pools.
AEDs and children
Parents often worry an AED is only for adults. It is not. AEDs can and should be used on children in cardiac arrest. Many devices include pediatric pads or a child mode that reduces the shock energy for kids under roughly 8 years old or 55 pounds. If pediatric pads are not available, standard adult pads can be used on a child — if the pads might touch on a small chest, place one on the front and one on the back. The AED's voice prompts will guide you, and using it is far better than not. Because drowning so often involves children, knowing this can be lifesaving.
How families can prepare
Take a CPR and AED course. Hands-on training from the American Red Cross, American Heart Association, or a local provider builds the muscle memory that makes you effective under stress. Reading is not a substitute for practice.
Notice AED locations. When you arrive at a pool, beach club, or rec center, glance for the AED cabinet so you know where it is before you ever need it.
Have an emergency plan. Know how you would call for help and who would fetch the AED. Our pool emergency action plan helps you set one up.
Watch for delayed symptoms. After any serious water incident, be alert to delayed breathing problems and seek medical care.
The bottom line for parents
An AED is a remarkable, easy-to-use device that can restart a heart, and it belongs in your mental toolkit alongside CPR. In a drowning, start CPR first and send someone for the AED; to use it on a wet person, move them to a dry spot, wipe the chest, attach the pads, and follow the voice prompts. AEDs are safe for children and forgiving to use — they only shock when needed. The best preparation is a certified CPR and AED class and a habit of noticing where the nearest device is. Knowing how this box on the wall works could one day help you save a life.
Frequently Asked Questions
Can you use an AED on someone just pulled from the water?
Yes, but first move the person to a dry area and quickly wipe their bare chest dry before attaching the pads. An AED can safely analyze and shock once the chest is dry and the person is not lying in water. Do not delay CPR while preparing the AED, and follow the device's spoken instructions.
Do you dry the chest before using an AED?
Yes. Water can interfere with the pads sticking and could let the shock spread across wet skin instead of through the heart. Quickly towel off the bare chest, make sure the person is out of standing water, and remove any pooled water under them before placing the pads.
Does an AED replace CPR in a drowning?
No. CPR comes first and is the priority in a drowning, because the cardiac arrest is usually caused by lack of oxygen. Start CPR immediately, send someone for the AED, and use it as soon as it arrives while continuing CPR between prompts. The two work together.
Are AEDs safe to use on children?
Yes. AEDs can be used on children, and many have pediatric pads or a child mode that lowers the energy for kids under about 8 years or 55 pounds. If pediatric pads are not available, standard adult pads can be used, placing one on the chest and one on the back if needed. The device will guide you.