Can You Use a Defibrillator on a Child or Baby?

Yes. If a child or baby has collapsed and is not breathing normally, an automated external defibrillator (AED) can be used, and using one quickly gives them the best chance. The machine analyses the heart rhythm and tells you what to do, so you do not need to make a clinical judgement. What changes with a child is the size of the shock and where the pads go.

Use child pads or a child setting if the device has one. Resuscitation Council UK advises using an AED with a paediatric attenuator for children below eight years old if possible, and the standard AED if not¹. The British Red Cross says that for children aged one to eight, paediatric pads should be used, and if they are not available, standard pads should be placed with one on the centre of the chest and one on the centre of the back². The Scottish Ambulance Service states that paediatric pads or programmes typically decrease the output of the machine to 50 to 75 joules³.

The most important thing is not to wait. If there is no child option, use the adult pads. The Resuscitation Council UK guide for communities states that adult pads and energy can be safely used on a child if this is the only resource available, taking care that the pads are not in contact with each other when delivering a shock⁴. Start CPR, send someone for the nearest defibrillator, and follow its spoken instructions.

Yes, an AED can be used on a child: what to do first

The sequence is the same as for an adult. Check for danger, check whether the child is responsive and breathing normally, and if they are not, start CPR and ask someone to fetch the nearest AED⁷. The NHS says to check for hazards, such as electrical equipment or traffic, before starting⁸.

When the AED arrives, switch it on and follow the prompts. The British Heart Foundation advises placing the pads on immediately and turning the machine on, following its instructions, and using child mode and child-sized pads if available. If you do not have a defibrillator, keep doing CPR⁶. The Resuscitation Council UK 2025 First Aid Guidelines say that if an AED is available, dry the chest quickly and follow the device prompts to apply and use it, which matters after a drowning⁹.

A defibrillator is a portable machine that can shock the heart back into normal rhythm². It is designed to be used by anyone, even without training, and is often found in workplaces, schools, gyms and other public areas¹⁰. The Scottish Ambulance Service says AEDs are designed to be safe and accessible for everyone¹¹.

Children under eight: paediatric pads, child key or child switch

For a child aged one to eight, the aim is to use the child option. The British Red Cross says that if the child is one to eight years old, use paediatric pads, placing one pad in the centre of the child's back and the second over the centre of their chest². The Resuscitation Council UK guide for communities gives the same principle: adult pads and energy can be safely used on a child if this is the only resource available, but pads must not touch each other when the shock is delivered⁴.

Different machines provide the child option in different ways. Some have a switch or key; some use separate pads. The Mediana A16 semi-automatic AED, as described by the retailer Red Cross First Aid Training, has the ability to change from adult to child mode with one button¹². The Philips HeartStart FRx works differently: when treating an infant or child, you insert the optional infant/child key and the FRx adjusts instructions and therapy¹³. The ZOLL AED Plus uses paediatric pads: the maker states that paediatric patients under 8 years old or under 25kg use Pedi-Padz II⁵.

If you are responsible for a defibrillator, check which of these it uses before you need it, and keep the child pads or key with the device. The Resuscitation Council UK recommends that all school children are taught CPR and how to use an AED⁴.

Babies under one year old: when an AED may still be used

The advice for babies is where people most often get confused, because different official pages phrase it differently. NHS Inform states that AEDs can be used on adults and children over 1 year¹⁴. Its baby CPR page, covering a baby under one year, says you can ask someone to get an automated external defibrillator if there is one nearby¹⁵. The British Red Cross says an AED can be used on children over a year old².

Read together, these are not instructions to withhold an AED from a baby. They reflect that cardiac arrest in babies is uncommon and that the evidence base is thinner. Resuscitation Council UK guidance, which underpins UK training, says to use a paediatric attenuator for children below eight years old if possible, and the standard AED if not¹. A baby is below eight. If a baby is unresponsive and not breathing normally, start baby CPR, send for the AED, and use it when it arrives, following the prompts.

The practical points for a baby are the same as for a small child. Use child pads or a child setting if the device has one. If it does not, use the adult pads, placing them so they do not touch each other⁴. The British Red Cross advises that if you have used a defibrillator, you should leave it attached¹⁶. The same applies to a baby: leave the pads on and the machine connected until ambulance staff take over.

How AEDs are made child-friendly

A child-friendly AED does two things: it lowers the energy of the shock, and it may adjust the pad position. That is the "paediatric attenuator" in practice. It is not a different machine; it is a setting, a key or a set of pads that changes what the same device delivers. All AEDs sold can be used on children using either the correct child electrode pads, child key or child switch where available¹³.

The pad position matters because a child's chest is small. The British Red Cross gives two placements depending on size. For a larger child, more than 25kg in weight and about eight years of age, the first pad goes on the upper right side below the collarbone and the second on the child's left side below and in line with their armpit. For a smaller child, less than 25kg and under about eight years of age, the first pad goes in the middle of the front of the chest and the second on the child's back between their shoulder blades⁶. The St John Ambulance guidance for infants and smaller children uses the same chest-and-back approach¹⁰.

Some devices are built with child use in mind from the start. The ZOLL AED 3 has child pads fitted to the device, along with audio and visual prompts and a CPR metronome¹. The iPAD SP1 fully automatic AED has a quick switch between adult and child mode¹⁷. The Mediana A16 Core HeartOn AED, in the maker's own description, can change from adult to child mode at the touch of a button¹⁸.

None of this replaces reading the device. The Resuscitation Council UK guide to AEDs explains that AEDs can be used anywhere, by anyone, to try to save the life of a person who has a cardiac arrest¹⁹. The machine's prompts are the instruction that matters in the moment.

Checking a public defibrillator before you need it

A public access defibrillator is an AED designed for use by anyone in a cardiac emergency²⁰. Most are registered with the local ambulance service so that 999 call handlers can direct people to them. In Northern Ireland, the Northern Ireland Ambulance Service explains how community AEDs are registered and supported²⁰.

If you look after a defibrillator at a school, sports club or village hall, check it as part of a regular routine. That is all the more reason to know what is in the case: a device bought for adults may have no child pads.

• Check whether the case contains child pads, a child key or a child switch, and where they are kept.
• Check the pad and battery expiry dates; the HeartSine Pad-Pak combines battery and electrodes in one cartridge with a single expiry date²¹.
• Check that the device is registered with the ambulance service if you want it available to the public²⁰.
• Check that the cabinet code or key is known to the people who might need it.

If you are choosing a defibrillator for a home, club or village, the child option is one of the specifications worth comparing. The guide to choosing a defibrillator sets out what else to weigh. For the general principles of using any AED, see Defibrillators (AEDs): What They Do and How to Use One, and for finding the nearest one, see Public Access Defibrillators.

HeartSine and other makes: what the child option looks like

HeartSine samaritan defibrillators use a Pad-Pak, which the maker describes as an integrated battery and electrode single-use cartridge with one expiration date, simplifying maintenance and removing the need for a separate battery²¹. That design is convenient, but it means the child option depends on the model and the pads supplied. If you own or manage a HeartSine unit, check its user manual for the child option that applies, and keep the right pads with the device.

Other makers describe their child provision plainly. The Philips HeartStart FRx uses an optional infant/child key that adjusts instructions and therapy¹³. The ZOLL AED Plus uses Pedi-Padz II for paediatric patients under 8 years old or under 25kg⁵. The Mediana A16 has a one-button change between adult and child mode¹². The iPAD SP1 has a quick switch between adult and child mode¹⁷.

Availability is a separate question. HeartSine was established in 1998 and is now a division of Stryker²². Ask about lead time if you are buying for a community site.

Where the official guidance comes from

The guidance in this article comes from Resuscitation Council UK, NHS ambulance services, NHS Inform and the British Red Cross. Resuscitation Council UK publishes the 2025 First Aid Guidelines, which include the instruction to dry the chest quickly and follow the device prompts if an AED is available after a drowning⁹. It also publishes a guide to automated external defibrillators for communities, which covers adult pads on children and the need to keep pads apart⁴.

NHS ambulance services publish public instructions. The North West Ambulance Service advises using an AED with a paediatric attenuator for children below eight years old if possible, and the standard AED if not¹. The Scottish Ambulance Service public access defibrillator information pack covers pad and battery life, device features and the encouragement for schools to have an AED³. The Northern Ireland Ambulance Service explains community AED registration²⁰.

The British Red Cross and St John Ambulance provide the practical steps most households will follow. The British Red Cross child first aid page gives the pad placements for larger and smaller children and the advice to leave the defibrillator attached⁶. St John Ambulance gives the same chest-and-back placement for infants and smaller children¹⁰. The British Heart Foundation explains that child and baby CPR differs from adult CPR²³.

For the wider picture, the 2025 Resuscitation Guidelines: What Changed for Bystanders explains what the latest guidance means in practice. If you want to learn CPR and AED use, the guide to learning CPR free online covers the free options, and the guide to first aid courses covers training. The Resuscitation Council UK works with GoodSAM so that people who complete its Lifesaver scenarios can sign up as volunteer cardiac responders⁴.