A person suddenly collapses at work, on a playing field, or in a classroom. They are unresponsive and not breathing normally. In that moment, knowing how to use AED safely can help you act with purpose while emergency medical services are on the way. An automated external defibrillator, or AED, is designed to guide everyday responders through the process with clear voice prompts. You do not need to diagnose a heart rhythm or decide whether a shock is appropriate. The AED analyzes the rhythm and makes that decision.
The priority is not perfection. It is recognizing cardiac arrest quickly, calling 911, beginning CPR, and using the AED as soon as it is available.
Start With Scene Safety and a Quick Assessment
Before approaching the person, look for immediate dangers. Traffic, live electrical hazards, fire, unstable structures, violence, or a hazardous spill can put both the victim and rescuers at risk. If the area is unsafe, do not enter until it is safe to do so or help can move the person without creating additional danger.
Once the scene is safe, check whether the person responds. Tap their shoulders and speak loudly: “Are you okay?” If there is no response, check for normal breathing for no more than 10 seconds. Occasional gasps, snorting sounds, or irregular breaths are not normal breathing. They can occur during cardiac arrest and should be treated as an emergency.
Call 911 immediately, or point to a specific bystander and give a clear instruction: “You in the blue shirt, call 911 and bring the AED.” Assigning a task to one person is more effective than asking a crowd generally for help. If you are alone with an adult victim, call 911 and retrieve an AED if one is nearby, then return to begin care. Follow dispatcher instructions if they are available.
Begin CPR While the AED Is Being Retrieved
Start high-quality CPR as soon as you determine the person is unresponsive and not breathing normally. Place the heel of one hand in the center of the chest, place your other hand on top, and keep your arms straight. Push hard and fast at a rate of 100 to 120 compressions per minute, allowing the chest to rise fully after each compression.
For trained rescuers, give 30 compressions followed by 2 breaths. If you are not trained or are unwilling or unable to give breaths, hands-only CPR is appropriate for most adults who suddenly collapse. Keep interruptions as short as possible. CPR keeps some blood moving to the brain and heart, but an AED may be needed to restore a shockable heart rhythm.
If more than one trained person is present, switch the person giving compressions about every two minutes, or sooner if fatigue affects compression quality. Make the switch quickly so chest compressions do not stop for long.
How to Use an AED Safely Step by Step
AEDs vary slightly by manufacturer, but they are built to be used under pressure. As soon as the device arrives, turn it on and listen. Most units will speak to you and may display images showing exactly what to do.
Expose and Prepare the Chest
Place the AED beside the person, ideally near their upper body. Continue CPR while another responder turns the device on and prepares the pads. Remove clothing from the chest so the pads can stick directly to bare skin. If the chest is wet from sweat, rain, or water exposure, dry it quickly with a towel or clothing. Do not delay AED use unnecessarily, but pads must adhere well for the device to work properly.
If the person has a medication patch on the chest, such as a nitroglycerin patch, do not place a pad directly over it. Use gloves if available, remove the patch, and wipe the area before applying the pad. If you see a noticeable implanted pacemaker or defibrillator under the skin, often near the collarbone, place the AED pad at least one inch away from the device rather than directly over it.
A very hairy chest can prevent good pad contact. Many AED kits include a razor. Quickly shave only the areas where the pads will go, or apply a pad firmly, pull it off to remove hair, and apply a new pad. The goal is good contact without turning a short preparation task into a long delay.
Apply the Pads Correctly
Open the pad package and follow the diagrams. For most adults, place one pad on the upper right side of the bare chest, below the collarbone. Place the other pad on the lower left side of the chest, below the armpit. This placement allows the electrical current to travel through the heart.
For children, use pediatric pads or a pediatric dose attenuator when available and appropriate for the child’s age or size. Follow the instructions printed on the AED and pads. If pediatric pads are not available, adult pads may be used according to current emergency response guidance. Make sure the pads do not touch each other. For a very small child or infant, pads may need to be placed on the front and back of the chest if the manufacturer’s diagrams direct that placement.
Clear the Person for Analysis
Once the pads are attached, the AED will tell you to stop CPR so it can analyze the heart rhythm. Say clearly and loudly, “Everybody clear.” Look to make sure no one is touching the person, including anyone holding their hand, leaning over them, or touching the stretcher or bed.
This pause is necessary because movement can interfere with the AED’s analysis. Keep it brief. Do not touch the person while the device is analyzing, even if they are on a metal surface. A metal surface alone is not usually a reason to move them, as long as no one is in contact with the person during analysis and there is no active electrical hazard.
Deliver a Shock Only When the AED Directs You To
If the AED advises a shock, make sure everyone remains clear. State it again: “Clear.” Visually check the entire person before pressing the flashing shock button, if the device requires you to press one. Some AEDs deliver the shock automatically after giving a warning.
Never touch the person during shock delivery. Once the shock has been delivered, or if the AED says no shock is advised, immediately resume CPR. Do not pause to check for a pulse unless the person begins showing clear signs of life, such as normal breathing, movement, or responsiveness. The AED will usually prompt another rhythm analysis after about two minutes of CPR.
Situations That Can Feel Complicated
A person who collapses in water should be moved out of the water before AED pads are applied. Dry the chest, then use the AED. Rain alone does not mean you should wait, but protect the device from standing water when possible and follow its prompts.
If the person is pregnant, use the AED as you normally would. Sudden cardiac arrest remains life-threatening, and prompt CPR and defibrillation offer the best chance for both the patient and the pregnancy.
If the person has a pierced chest area, avoid placing a pad directly over metal jewelry if possible. If there is a bra with an underwire, remove it only if it prevents proper pad placement. Do not lose valuable time on clothing or jewelry that does not interfere with the pads.
An AED should not be used on someone who is awake, responsive, and breathing normally. It is for an unresponsive person who is not breathing normally. If you are unsure, call 911, start with the assessment, and follow dispatcher and AED instructions.
Keep the Team Focused Until Help Arrives
Emergency scenes can become noisy quickly. One person should take charge of communication, relay updates to 911, and direct bystanders to give space. If available, have someone meet EMS personnel and lead them to the exact location.
Continue cycles of CPR and AED analysis until the person starts breathing normally and responding, EMS takes over, another trained responder relieves you, or you are physically unable to continue. If the person begins breathing normally but remains unconscious, place them on their side in a recovery position if there is no concern for major trauma, and continue monitoring them until help arrives.
Training Builds Speed, Not Just Knowledge
Reading the steps is valuable, but hands-on practice makes a major difference when stress is high. Quality CPR and AED training lets you practice pad placement, effective chest compressions, team communication, and the short pauses required for AED analysis. It also helps employers, teachers, coaches, and community members understand the certification requirements that apply to their role.
For Richmond-area teams and individuals, Richmond Training Concepts provides practical AHA and HSI training led by instructors with real emergency services experience. The goal is not to make an emergency feel routine. It is to make your first actions clear enough that you can help when seconds matter.
The best time to learn where the nearest AED is located and how it works is before someone needs it. A familiar device, a practiced response, and the willingness to step forward can turn a frightening emergency into a coordinated effort to save a life.