Danger, the call, and recognising cardiac arrest

Lesson 1 left you in a kitchen, with your father on the floor and one question: what do I do first? Its answer was to call, on speaker. This lesson is the next sixty seconds. They matter more than any others, because almost everything that saves a person in cardiac arrest depends on how fast those seconds go: how soon someone phones, how soon someone recognises what is happening, and how soon someone starts pushing on the chest. The hard part is not the pushing. It's knowing that this is the moment to push, when the person on the floor seems to be breathing, or twitching, or looking at you.

The minimum, if you read nothing else

If someone collapses and won't respond, three things matter more than everything else in this course. Call your emergency number with the phone on speaker. If they aren't breathing normally, or you aren't sure, push hard and fast in the centre of the chest. And don't stop until the ambulance crew are there and able to take over.¹⁴

RCUK's public version of its 2025 adult guidelines says much the same in three words, its "3 steps to save a life": Check, Call, CPR.¹ The American Heart Association's 2025 guidelines say the same thing in their own order, which this lesson sets out below.² The rest of this lesson, and lessons 3 to 5, fill in each step. None of them changes it.

First, is it safe for you?

Every first aid sequence starts with you, not the casualty. St John Ambulance, which teaches the UK's primary survey as DR ABC (Danger, Response, Airway, Breathing, Circulation), puts it in one line: "Before approaching the casualty, always make sure the area is safe."⁵ The American Red Cross opens its own sequence the same way: "First, CHECK the scene for safety."⁶ RCUK's public steps begin with the question "Is it safe to approach?"¹

You matter, but there's a harder reason too. A rescuer who's hit by a car, or shocked, or pulled into water, turns one casualty into two and leaves nobody to call. The dangers the course's sources name are ordinary ones:

• Traffic. A person collapsed on or beside a road. Car Basics and Personal Safety, later this term, cover the roadside.
• Electricity. Make sure the power is off before you touch someone in contact with a supply (the American Red Cross and St John, in their burns advice).¹⁶
• Water. Do not go into the water to reach someone unless you are trained; reach with something, or throw something that floats (RCUK 2025).¹⁴ Lesson 6 covers drowning.
• Fire, and violence. If the scene is burning or someone there is dangerous, keep your distance and make the call from somewhere safe. Personal Safety, later this term, covers violence and threat.

One danger is easy to miss because you can't sense it. Carbon monoxide is colourless and has no smell, and the NHS's list of its symptoms includes headache, dizziness, feeling sick, weakness, confusion and shortness of breath, which tend to ease when the person leaves the building.¹⁵ So if you find someone collapsed indoors near a boiler, a heater or a running engine, and especially if you start to feel unwell yourself, get outside and call 999 from there. The NHS's advice to anyone who may have breathed carbon monoxide is to go outside, and that includes you.¹⁵

Are you OK?

Once it is safe, find out whether the person responds. St John's version: kneel beside them, gently shake their shoulders and ask, "Are you OK?"⁵ The American Red Cross calls it "shout-tap-shout".⁶ You are asking one question: does this person react to you at all? St John counts someone as responsive if they open their eyes when you ask them to, or give some other gesture in answer; if they don't respond to you in any way, they're unresponsive.⁵ The reaction has to be to you. Open eyes, a groan, or a movement that has nothing to do with what you said or did doesn't count, and later in this lesson you'll see why: people in cardiac arrest can have their eyes open and make groaning sounds. Most of this lesson is about the person who doesn't respond.

A person who does not respond is not necessarily in cardiac arrest. They might be drunk, deeply asleep, having a diabetic low, or recovering from a faint. RCUK 2025 puts it plainly: "Suspect cardiac arrest in any person who is unresponsive."¹ It says suspect, and what you do next is where the two countries' guidance divides.

When to call: the one real difference in the first minute

You've found someone unresponsive. Do you check their breathing first and call once you know it is an arrest, or call first and check while the phone rings?

The UK and European order. RCUK's 2025 adult guidelines list this among their changes: "Call 999 for any unresponsive person. Rescuers no longer need to confirm abnormal breathing before calling. Initiate the call first, then assess breathing while waiting for the call to be answered."¹ The ERC's public guide gives the reason in plain words: "Cardiac arrests are not always recognised by bystanders on scene. In fact, most often, it is the emergency medical service (EMS) operator on the phone who does."⁴ RCUK says the same from the other side: "Recognition of cardiac arrest can be challenging," and the call handler's role "is critical to early recognition of cardiac arrest and initiation of CPR."¹

On their reasoning, the breathing check you'd have done alone, uncertain and frightened, is one a trained person does better with you on the line, so doing it yourself first costs time and adds little. That is also why RCUK tells you to make the call yourself if nobody else can, "before assessing whether breathing is normal."¹

The US order. The AHA's 2025 adult guidelines keep recognition first. Their first recommendation for lay rescuers: "If an adult is unconscious/unresponsive, with absent or abnormal breathing (ie, only gasping), the lay rescuer should assume the person is in cardiac arrest" (AHA 2025, COR 1, LOE C-LD).² Then: "After identifying an adult in cardiac arrest, a lone responder should activate the emergency response system first, then immediately begin CPR, beginning with chest compressions" (COR 1, LOE B-NR); and, for the usual case, "a lone rescuer with a mobile phone should activate the emergency response system and immediately begin CPR" (COR 1, LOE C-LD).² Lesson 1 showed how to read these labels, and lesson 4 explains the evidence letters; for now, COR 1 is the AHA's strongest class, the one that says "should".

The AHA says openly that the order of call and CPR has not been shown to change survival. It reports that a large observational study of more than 17,000 patients found no difference in survival to discharge between CPR started before the call and CPR started after it, and it gives its reason for recommending the call first anyway: "Our recommendation values the practical considerations of timely emergency medical response dispatch and the availability and value of remote assistance to improve the quality of CPR."²

Neither is wrong. With a phone in your pocket, both orders put you on speaker to a trained call handler within seconds, and both start compressions the moment the person is judged not to be breathing normally. The difference is whether the breathing check comes a few seconds before you dial or a few seconds after. Follow the guidance of the country you're in, because that is the order your call handler and your class will use.

Speaker on

Both countries tell you to use the speaker, and it is worth seeing why it's in the course's callout at the top of every lesson.

In the US, the AHA's 2025 adult guidelines say: "Use of the 'hands-free' speaker feature on most cell phones, when and where available, can help with near-simultaneous activation of emergency response and initiation of CPR."² That's from the explanation beneath the COR 1 recommendation above, the one telling a lone rescuer with a mobile phone to call and begin CPR straight away. The AHA's reasoning is that "most lay rescuers will likely have mobile phones with hands-free options," so calling and CPR can happen "at nearly the same time."² The American Red Cross's Check, Call, Care page says the same in one line: "Once 911 has been called, put the dispatcher on speaker phone."⁶

In the UK, RCUK's 2025 adult guidelines say: "If you have a mobile phone, activate the speaker function and call 999 without delay."¹ The ERC's public guide gives the purpose: speaker mode lets you talk to the dispatcher while your hands are free for the person.⁴

CPR takes both hands, locked together on the chest. A phone held to your ear takes one of them. Without the speaker you have to choose between talking to the one person who can coach you and doing the one thing that keeps blood moving, and every second spent switching is a second of no compressions. Lesson 3 shows what pauses cost.

What the call handler needs from you

The person who answers has different names in different places. The UK says call handler, the US sources say call-taker or dispatcher. It is the same job, and this course uses "call handler" for both.

Their first questions are predictable, and knowing them in advance is what the practice exercise below is for.

• In the US, 911.gov lists what a call-taker may ask for: "The location of the emergency, including the street address", "The phone number you are calling from", "The nature of the emergency", and details such as "a description of injuries or symptoms."⁷
• In the UK, the NHS's page When to call 999 lists "the location of the emergency (for example, the postcode or any landmarks)", "what has happened" and "your contact number."⁸ South Central Ambulance Service says the first things its call takers ask are "if the patient is breathing and conscious" and "your location."⁹ The ERC's guide gives the same opening questions: "Is the person conscious?" "Are they breathing normally?"⁴

Location, and whether the person is conscious and breathing, come first. The NHS and 911.gov list location first; South Central Ambulance Service asks about breathing and consciousness first and location straight after, so that it can "immediately start the dispatch process".⁹ Either way, help can be on its way while you are still describing what happened, so have the address ready. After that, answer what you're asked and let them lead. RCUK 2025 says that once arrest is recognised, call handlers "should provide CPR instructions to all callers," and that they "should assume the caller does not know how to perform CPR and provide chest-compression-only instructions."¹ Compression-only means pushes on the chest with no rescue breaths; lesson 4 covers breaths. Then, once CPR is underway, they ask whether there is an AED at the scene, and if there are other people with you, they can guide someone to the nearest one.¹

The call handler is a coach, not a switchboard. Telephone instructions for CPR are one of the few things in this field that every body recommends strongly, even though ILCOR rates the evidence behind them as very low certainty, the kind of gap lesson 4 explains. ILCOR, the international committee whose evidence reviews both countries' guidelines draw on, recommends that dispatch centres be set up to give CPR instructions for adults in cardiac arrest, and that dispatchers give them when needed (strong recommendation, very low certainty evidence), and that for adults the instructions be compression-only (strong recommendation, low certainty evidence). Both are older recommendations that its 2025 summary keeps unchanged.¹¹ The AHA's 2025 guidelines recommend that call-takers advise compression-only CPR for adults (AHA 2025 Part 4, COR 1, LOE A, the top level of evidence).¹² The US 911 programme tells callers the same thing: "Many 911 centers can tell you exactly what to do until help arrives," CPR included.⁷ You do not need to remember a technique perfectly if someone is counting with you.

And don't end the call early. 911.gov: "Do not hang up until the call-taker instructs you to do so."⁷

How they find you

In the UK, you may not need to know exactly where you are. Most modern smartphones send their position during a 999 call through Advanced Mobile Location. As one ambulance service puts it, "AML is not an app; it does not require any action from the caller as it is built into most modern smartphones", and its accuracy is "generally around or below 30meters but can be as low as 5 meters", against a cell-tower estimate of around 3 kilometres.⁹ Some UK ambulance services, including South East Coast and South Central, also use what3words, which names a precise spot with three words. If you cannot say where you are, South East Coast's call handlers can text you a link that finds your position: "There is no need for them to download the W3W app."⁹ South Central suggests downloading it in advance,⁹ but you don't need it.

In the US, this course didn't research how 911 centres locate a mobile phone, so it makes no claim either way. 911.gov asks for the location, including the street address.⁷ If you don't know it, a landmark, cross street or business name is this course's suggestion, and then answer the call-taker's questions.

Across the EU, 112 works everywhere, free, from fixed and mobile phones, alongside each country's own numbers.¹⁰ In the UK both 999 and 112 work.⁵

Alone, with no phone

It happens: a flat battery, no signal, a phone in a coat upstairs. RCUK 2025 says to shout for help and keep assessing breathing, and then: "If you think no one will come to help, then you will have to leave the person and call 999. Do this as quickly as possible."¹ When you come back, if they're still unresponsive and not breathing normally, start CPR at once.¹ The AHA says that when no phone is at hand, local circumstances decide whether to delay CPR to go for help, and that the importance of timely CPR must be stressed.² It is a rare and hard choice, and RCUK's advice is to make it fast.

Not alone: give people jobs

Lesson 1 gave you the sentence for a crowd: point at one person for the call and another for the defibrillator. The AHA builds the same step into its guidance, noting that "a second lay rescuer can be instructed to call 911."² Two details make the jobs work. The caller brings the phone to you, on speaker, and puts it by the person's head, so the call handler can hear you and you can hear them while your hands are on the chest. And the person sent for the defibrillator brings it straight to you, because RCUK's third step is "As soon as an AED is available, attach it and follow the AED instructions."¹ With only one helper, they make the call and you start.

One thing not to do: do not send someone to search a website for the nearest defibrillator. The UK's public lookup, defibfinder.uk, says it "is not intended for use in an emergency."¹³ The UK's national register of defibrillators, The Circuit, exists so that "ambulance service call handlers" know where each registered one is during a 999 call,¹³ and RCUK says the call handler should be able to direct callers to the nearest accessible AED.¹ Ask them. Lesson 5 covers the defibrillator itself.

Recognising cardiac arrest

Both countries use the same two signs: the person is unresponsive, and not breathing normally. The first you've already checked. The second is where people go wrong, and the guidelines say so in almost the same words. The AHA: agonal breathing "is cited as a common reason for lay rescuers to misdiagnose a patient as not being in cardiac arrest."² The ERC's guide: "One of the biggest barriers to a bystander stepping in to help is when the victim seems to be breathing."⁴

Gasping is not breathing

In the first minutes of many cardiac arrests the person keeps making breathing movements. The AHA defines them: "Agonal breathing is characterized by slow, irregular gasping respirations that are ineffective for ventilation."² Ineffective for ventilation means they do not move useful air in and out. It's common: the AHA puts it at up to 40 to 60% of cardiac arrests outside hospital, and it "diminishes the longer a person is in cardiac arrest."² The guideline text this course read describes agonal breathing and does not explain what produces it, so this lesson does not either.

The words bystanders use for it are revealing, because none of them sounds like an emergency. The AHA: "abnormal breathing, snoring respirations, and gasping."² The ERC's public guide: "They appear to be gasping, moaning, sighing, gurgling, groaning, snorting, or struggling to breathe. This is not breathing!"⁴ RCUK 2025: "Slow, laboured breathing, as well as other abnormal patterns such as agonal gasping or panting, must be recognised as signs of cardiac arrest."¹

So "not breathing normally" is a wider category than "not breathing". If an unresponsive person is making any of those sounds, you treat it as arrest. If you are unsure whether what you are seeing is normal, the call handler will help you decide, which is the whole point of having called.

Jerking, then stillness

A seizure and an arrest can look alike for those few seconds. The check that separates them comes afterwards: once the movement stops, is the person breathing normally? Lesson 14 teaches first aid for seizures that are not arrest.

Panting, with eyes open

RCUK added this in 2025, and it matters most at sports grounds: "Exercise is a common precipitant of cardiac arrest. The 2021 guidelines emphasised descriptions of slow or laboured breathing as indicators of abnormal breathing. For 2025, we recognise that early after the onset of cardiac arrest, athletes may display a near-normal or panting breathing pattern."¹ The ERC's guide adds a detail that makes it harder still: people who arrest in the middle of vigorous exercise or play "may appear to be breathing heavily, and their eyes are often open."⁴

Think about what an onlooker sees. A player has just been running hard. He is on the ground, breathing fast, eyes open. Every instinct says "winded". The 2025 guidance says that if he does not respond to you, that picture is compatible with cardiac arrest.

Feeling for a pulse

That is why lay rescuers do not check a pulse. The AHA's 2025 paediatric guidelines say lay rescuers "should not check for a pulse" (COR 1, LOE C-LD), and the adult guidelines say recognition by lay rescuers "is, therefore, based primarily on level of consciousness and respiratory effort rather than using a pulse check."³² RCUK's lay steps contain no pulse check at all: response, then breathing.¹ The pulse check survives in the guidelines only for healthcare professionals, and even they are told to take no more than 10 seconds.²

When in doubt, start

RCUK 2025: "If there is any doubt, assume cardiac arrest and start CPR."¹ The AHA gives the reason: "The benefit of providing CPR for someone in cardiac arrest far outweighs any risk associated with providing chest compressions to someone who is not."² Lesson 3 gives the numbers on that risk. For now, hold on to the asymmetry the AHA describes: the harm of missing an arrest is far bigger than the harm of compressions on someone who turns out not to need them.

The kitchen floor, in both countries' order

Go back to the kitchen from lesson 1. You've come downstairs and found your father, who's in his sixties, on the floor by the table. The same minute follows twice, once for each country. (The spoken lines are this course's illustration, built from the questions the NHS, South Central Ambulance Service and 911.gov say call handlers ask. They are not from a real call.)

The first minute, as each country's 2025 guidance orders it. The outlined first and last boxes are shared; the shaded middle two are where the order differs. Drawn by this course from the sources named in each box.

In England. You call his name, kneel, shake his shoulders and ask, "Dad, are you OK?" Nothing. Before doing anything else you take your phone out, put it on speaker and dial 999 (RCUK 2025),¹ and set the phone on the floor by his head so you and the call handler can hear each other. While it rings, you look at his chest and listen. He makes a single deep, slow gasp, then nothing for several seconds, then another.

The operator first asks which service you need, and you say "Ambulance".⁹ Then a likely shape, in the order South Central Ambulance Service gives:⁹

"Is the patient breathing, and are they awake?"

"He won't wake up. He's sort of gasping. Every few seconds."

"What's the address of the emergency?"

"14 Mill Lane, Ashford. It's my dad, he's collapsed in the kitchen."

That word, gasping, is what the call handler is listening for. Slow, irregular gasps in someone unresponsive are a sign of cardiac arrest (RCUK 2025),¹ so you're told to start compressions and are counted through them, compression-only, on speaker (RCUK 2025).¹ Your phone may already have sent your position by AML.⁹ If someone else is in the house, the call handler will ask whether there's a defibrillator nearby and can direct them to the nearest registered one.¹

In Ohio. The same kitchen, the same father. You check that nothing in the room is dangerous, tap and shout, and get no response. You look at his chest: no normal breathing, only the same slow gasps. Under the AHA's 2025 guidelines that is enough to assume cardiac arrest (COR 1),² so you put the phone on speaker, call 911 and start compressions straight away, as a lone rescuer with a mobile phone should (COR 1).² The call-taker asks for the address, the number you're calling from and what has happened,⁷ and coaches you through compression-only CPR (AHA 2025 Part 4, COR 1).¹² You don't hang up until you're told to.⁷

Notice how little the two versions differ in time. In England, the breathing check happened during the ring. In Ohio, it happened just before the dial. In both, the call handler was on speaker and your hands were on his chest within the first minute.

The five-a-side game

This one is harder, because everything the friends see seems to say "he's fine".

A man in his forties is playing five-a-side football (a small-sided game on a small pitch) on a Thursday evening. He's been running hard for twenty minutes. He slows, sits down on the artificial grass and falls sideways. For a few seconds his arms and legs jerk. Then they stop, and he starts making loud, slow gasps. His eyes are open. One friend says, "He's having a fit." Another says, "He's breathing, get him on his side." They roll him into the recovery position and one of them goes to find his bag for his phone, to see if there's anyone to ring.

Take each observation in turn.

1. He collapsed during hard exercise. RCUK 2025: "Exercise is a common precipitant of cardiac arrest."¹ That does not mean it's an arrest, but it raises the stakes on everything that follows.
2. He jerked for a few seconds. A short burst of seizure-like movement can be the start of a cardiac arrest (RCUK 2025).¹ The friend who said "fit" was describing what he saw correctly and drawing the wrong conclusion from it. The rule is to check breathing once the movement stops.

What should have happened: someone checks that he doesn't respond, then calls on speaker, 999 at once in the UK (RCUK 2025), or 911 with compressions starting because the gasps mean arrest in the US (AHA 2025). He goes onto his back, someone pushes, and someone else fetches a defibrillator. The ERC's guide says a dispatcher may start by asking, "Are they breathing normally?"⁴ Hearing "loud gasps", the call handler would most likely have told them to start.

999, or 111?

Not every worrying situation is a 999 call, and the NHS runs a second number for the ones in between. NHS 111 is for when you are "not sure if you need to call 999."⁸ An unresponsive person is not one of those cases: RCUK's rule is to call 999 for anyone unresponsive.¹

Two NHS pages show where the lines fall. The fainting page lists the reasons to call 999 after a faint: the person is not breathing, can't be woken within a minute, hasn't fully recovered or has difficulty with speech or movement, has chest pain or palpitations, has seriously hurt themselves, is having a seizure, or fainted while exercising or lying down. If none of those applies, its advice is to see a GP, because a faint should be checked.¹⁵ Lesson 7 covers fainting properly. The carbon monoxide page draws the line between 999 and 111. If you think you might have symptoms, go outside and call NHS 111. Call 999 if someone who has been exposed finds it hard to breathe, has suddenly become confused, has lost consciousness, feels weak, or has chest or muscle pain.¹⁵

The NHS page also gives a list of things to do while you wait for an ambulance: turn on the lights, open the curtains, put on your hazard lights if you are in a car, lock away pets, gather the person's medicines, and "call 999 again if the person's condition changes."⁸ The last instruction is the one people forget, because by then the first call may have ended. And if the person becomes unresponsive and stops breathing normally while you wait, call 999 again on speaker and start CPR: the first minute, from the beginning.

This course didn't read a US source on non-emergency lines, so it gives no US equivalent. The US poison line comes in lesson 14.

Three slogans, one order

You will meet the first minute packaged in three sets of initials, and it helps to see that they teach the same order in different words.

Two differences are worth seeing. St John's page, clinically reviewed in April 2025, still has you check breathing "for no more than 10 seconds" before you call,⁵ and the American Red Cross's First Aid Steps page has you check responsiveness, breathing and bleeding before calling, which matches the AHA's recognise-first order.⁶ RCUK's October 2025 guidelines put the call before the breathing check.¹ The St John page predates those guidelines by six months and may not have caught up yet. If you are in the UK and the two disagree, RCUK's 2025 guidelines are what your call handler will be working from.

What people get wrong

"Gasping means they're breathing." It's one of the commonest reasons bystanders don't start (AHA 2025; ERC 2025).²⁴ Slow, irregular gasps are agonal breathing, "ineffective for ventilation" (AHA 2025), and a sign of arrest.²

"Check for a pulse first." Lay rescuers don't. The AHA's adult guideline bases their recognition on response and breathing "rather than using a pulse check", and its paediatric guideline says lay rescuers "should not check for a pulse" (COR 1).²³ In the study the AHA cites, lay rescuers got the pulse right 47% of the time at five seconds.³

"Wait until you're sure." Neither country asks you to be sure. RCUK 2025: "If there is any doubt, assume cardiac arrest and start CPR."¹ And in the UK you don't even need to be sure before calling: call for anyone unresponsive.

"A seizure means it isn't cardiac arrest." A brief seizure-like episode can be how an arrest begins (RCUK 2025).¹ When the movement stops, check the breathing.

"Download what3words or they won't find you." In the UK, most smartphones send their position automatically, and if needed the call handler can text you a link. You do not need the app.⁹

"Look up the nearest defibrillator online." The UK's public lookup says it is not for emergencies. The call handler knows where registered AEDs are.¹³¹

"Hang up once you've given the address." The call handler is about to coach you through CPR and may send someone for a defibrillator. Stay on until you're told otherwise.⁷

Practice

Connections

Lesson 1 dealt with the reasons people hesitate. This lesson answers most of them with steps: you do not need to be sure, because the call handler helps you decide; you do not need to know CPR, because the call handler will count with you; and you don't need to decide whether it is a seizure or an arrest, because the check after the movement stops decides it. Lesson 3 takes "push hard and fast in the centre of the chest" and gives each number behind it. Lesson 5 is the defibrillator the helper went to find. Lesson 7 is the person who is unresponsive but breathing normally, and lesson 14 is the seizure that is not an arrest.

Two earlier courses meet this one here. Strength and Fitness told you when to stop exercising; this lesson is what a bystander does when someone didn't get the chance. And Sleep taught you to compare how strongly different guidelines recommend something. The "COR 1" beside the AHA's instructions is that idea again, and lesson 4 teaches the AHA's and ILCOR's labels properly.

Go deeper

• RCUK, 2025 Adult basic life support guidelines. The UK's current adult guidance on one free page, with its changes since 2021 listed at the top. This course read it in full. The sections on recognising arrest and on the call handler's role are short and worth reading in the original.
• ERC, The ERC Guidelines 2025 on Resuscitation for Everyone. The European Resuscitation Council's guide for the public, free as a PDF. This course read its adult, children's and special-circumstances pages in full and skimmed the rest. Its two pages on the "3 Cs" are the plainest account of recognising arrest that this course found.
• NHS, When to call 999. What the call handler will ask, what to do while you wait, and when 111 is the better number. Read in full.
• 911.gov, Calling 911. The US equivalent, from the federal 911 programme. This course read it from an Internet Archive capture of 7 September 2026, because the live site blocked automated reading; the page was last updated in January 2023.

Sources

1. Resuscitation Council UK, 2025 Resuscitation Guidelines: Adult basic life support, 27 October 2025, resus.org.uk . Read level: full, direct, re-read on 2026-09-24 for this lesson. Supports every RCUK 2025 quotation and instruction here: the three steps, the call-first change, recognition, the athlete's panting pattern, seizure-like activity, speaker mode, being alone without a phone, "If there is any doubt", and the call handler's role. It adapts the ERC's 2025 Adult BLS chapter, which this course cites through it.
2. M. E. Kleinman, J. E. Buick, N. Huber and colleagues, "Part 7: Adult Basic Life Support: 2025 American Heart Association Guidelines for CPR and Emergency Cardiovascular Care", Circulation 152 (suppl 2), 2025 . Read level: full, from the Internet Archive capture 20251026225858 (the live site blocks automated reading). Supports the recognition and calling recommendations with their COR and LOE, agonal breathing, recognition without a pulse check, the observational study and the AHA's stated reason, the speakerphone sentence, the second rescuer, and the benefit-over-risk sentence.
3. B. L. Joyner, M. Dewan, A. Bavare and colleagues, "Part 6: Pediatric Basic Life Support: 2025 AHA and American Academy of Pediatrics Guidelines", Circulation 152 (suppl 2), 2025. **Read level: full, from the Internet Archive capture 20251026203140.** Supports "should not check for a pulse" (COR 1, C-LD) and the accuracy figures, which come from studies the guideline cites and this course has not read.
4. European Resuscitation Council, The ERC Guidelines 2025 on Resuscitation for Everyone, lay guide, December 2025 . Read level: full, direct for the adult, paediatric and special-circumstances pages; the rest skimmed. Supports the 3 Cs, the lay words for agonal breathing, open eyes in exercise, the seizure warning, the dispatcher's questions and role, speaker mode, and CPR until the ambulance crew take over.
5. St John Ambulance, "How to do the primary survey (DR ABC)", clinically reviewed 28 April 2025. **Read level: full, direct.** Supports the danger and response checks, what counts as responsive, the 10-second breathing check, and 999 or 112.
6. American Red Cross, "Check, Call, Care: 3 Emergency Actions Steps" and "First Aid Steps", undated . Read level: full, direct. Supports the scene check, shout-tap-shout, the speaker line, the checks before calling, and care by condition and training.
7. 911.gov, "Calling 911" . Read level: full, from the Internet Archive capture 20260907153825. Supports what a call-taker asks, call-takers' instructions until help arrives, and "Do not hang up".
8. NHS, "When to call 999" . Read level: full, direct. Supports what the call handler wants, the while-you-wait list, and NHS 111.
9. South Central Ambulance Service, "999" page, and South East Coast Ambulance Service, freedom of information response 220805 on AML and what3words, 2023 . Read level: both full, direct. Supports asking for the ambulance service, the first questions asked, AML, and what3words.
10. European Commission, "112: the EU's emergency phone number" . Read level: full, direct.
11. J. E. Bray, M. A. Smyth, G. D. Perkins and colleagues for the ILCOR Basic Life Support Task Force, "Basic Life Support: 2025 International Consensus on CPR and ECC Science With Treatment Recommendations" . Read level: full, direct, from the accepted manuscript on ilcor.org, not the typeset Circulation article, so this lesson paraphrases it. Supports the dispatch-CPR recommendations with their strength and certainty.
12. C. Dezfulian, J. G. Cabañas, J. R. Buckley and colleagues, "Part 4: Systems of Care: 2025 AHA Guidelines", Circulation 152 (suppl 2), 2025 . Read level: partial, from the Internet Archive capture 20260208194135. Supports compression-only telephone instructions for adults (COR 1, LOE A). The web copy of the AHA's box on call-takers' recognition appears to carry text from another section, so this lesson gives no AHA recommendation on it.
13. Resuscitation Council UK, "The Circuit" . Read level: full, direct.
14. Resuscitation Council UK, 2025 Resuscitation Guidelines: First aid and Special circumstances, 27 October 2025 . Read level: partial, direct. Supports no recovery position in agonal breathing, and reach or throw.
15. NHS, "Carbon monoxide poisoning" (16 December 2025) and "Fainting" (17 August 2026). **Read level: full, direct.** Supports the carbon monoxide symptoms, "go outside", and its NHS 111 and 999 lines; and the fainting page's reasons to call 999 and its advice to see a GP.
16. American Red Cross and St John Ambulance advice on electrical burns . Read level: full, direct. Supports turning the power off before touching the person.
17. D. Cao, A. M. Arens, S. L. Chow and colleagues, "Part 10: Adult and Pediatric Special Circumstances of Resuscitation: 2025 AHA Guidelines", Circulation 152 (suppl 2), 2025. **Read level: partial, from the Internet Archive capture 20251027153841.** Supports "Effective CPR cannot be performed in the recovery (lateral decubitus) position."