UK First Heatwave 2026 Amber Alert: A Calm NHS Patient Guide to Staying Safe in the Heat

The UKHSA issued the first amber heat-health alert of 2026 across most of England from 22 to 28 May, with temperatures hitting 32-35C – the hottest May spell on record for several stations. Amber means the whole population is at increased risk, not just the most vulnerable.

Your phone buzzes on a Friday afternoon in late May. It is a Met Office amber heat-health alert. The bedroom is already 28C. Mum is upstairs with the window shut. The baby is napping under a thin sheet. The dog is panting on the kitchen tiles. And you are trying to remember what you are actually supposed to do.

This is a UK patient guide based on NHS, UKHSA and Met Office advice. On 22 May 2026 the UKHSA issued the first amber heat-health alert of the year for most of England – South West, South East, East Midlands, West Midlands, East of England and London – and it ran until 5pm on 28 May. Temperatures reached 32-35C, the hottest May spell on record for several stations.

The article covers four things: how to keep your home and body cool, how to spot the difference between heat exhaustion and heatstroke, who is most at risk and needs checking on, and exactly when to call 999. There is also a short section on medications that change how the body copes with heat, advice on babies in hot bedrooms, and a final FAQ.

What an amber heat-health alert actually means

The UKHSA and the Met Office run a joint heat-health alert system that grades from green to red. Each colour signals a different level of risk and a different set of recommended actions.

Green is routine summer. No special action needed. Yellow means vulnerable people are at increased risk and warrants targeted action by health and social care – more checks on care-home residents, adjustments to community nursing rotas. Amber means the whole population is at increased risk and the NHS will feel a real impact: more A&E attendances, more ambulance calls, possible cancellation of non-urgent operations and outpatient clinics. Red means significant risk to life even for healthy adults, and major disruption to NHS services.

The alert issued on 22 May 2026 and extended to 28 May was amber across six English regions. Met Office temperatures reached 32-35C in central and southern England – the hottest May spell on record for several stations. This was the first amber heat-health alert of 2026.

The numbers behind amber alerts are worth knowing. Early-warning modelling from the London School of Hygiene and Tropical Medicine and Imperial College London estimates that a typical UK heatwave week produces around 570 excess deaths, with 488 of those in adults aged 65+ and 314 in people aged 85+. The 2022 record-breaking heatwave – when the UK hit 40C for the first time – was linked to nearly 1,100 excess deaths in three days.

Take an amber alert seriously even if you feel fine. The people around you may not.

Heat exhaustion vs heatstroke – the difference that matters

Heat exhaustion is the warning sign. Heatstroke is the emergency. The two sit on the same spectrum, and learning to spot where someone is on it – and when they have crossed the line – is one of the most useful things you can carry into a heatwave.

Heat exhaustion happens when the body is overheating but is still managing to cool itself. The signs are: tiredness, weakness or dizziness; headache; nausea or vomiting; muscle cramps in arms, legs or stomach; fast breathing, fast heartbeat; pale, clammy skin; very thirsty; dark urine; temperature usually 38C or above. In children it can look different – unusually quiet, sleepy or irritable, losing their normal energy, “hitting a wall”. With cooling, fluids and rest, most people noticeably improve within 30 minutes.

Heatstroke means the body cooling system has failed. The signs are: still unwell after 30 minutes of cooling; temperature 40C or above; hot, DRY skin that is no longer sweating; fast heartbeat or breathing; confusion, slurred speech or lack of coordination; seizures or fits; loss of consciousness or unresponsive.

The clearest red flag is hot, dry skin in someone who was sweating a few minutes ago. Once sweating stops, the body has lost its main way of shedding heat and the core temperature can climb fast. Heatstroke can cause organ damage within hours. If you see these signs, call 999 straight away.

First aid for heat exhaustion – the NHS 4-step plan

If someone has signs of heat exhaustion, act quickly. The NHS lays it out in four clear steps.

• One – move them to a cool place. Indoors, into shade, in front of a fan or air conditioning, or near an open window if the air outside is cooler than inside.
• Two – get them to lie down with feet slightly raised, which supports blood flow back to the heart and brain.
• Three – get them to drink. Plain water is fine for mild cases. For someone who has been sweating heavily after sport, gardening or manual work, an isotonic sports drink or an oral rehydration sachet from the pharmacy replaces salt as well as water and is a better choice.
• Four – cool the skin. Spray or sponge with cool but not ice-cold water. Place cold packs wrapped in a thin tea towel under the armpits and around the neck for 10-15 minutes. Loosen tight or heavy clothing.

The person should start to feel better within 30 minutes. If they do not improve, or any sign of heatstroke appears, call 999. Do not give alcohol, caffeine or fizzy drinks. Do not give fluids to anyone who is vomiting or who has lost consciousness.

When to call 999 for heatstroke and what to do while you wait

Call 999 immediately if any of these are present: temperature 40C or above; hot, dry skin that is no longer sweating; confusion or slurred speech; lack of coordination; seizures or fits; loss of consciousness or unresponsive. While you wait for the ambulance, do everything you can to bring body temperature down. Move them to the coolest place you have – inside, shaded, in front of a fan. Remove outer clothing. Wrap in a cool wet sheet or sponge with cold water. Place cold packs wrapped in a thin cloth under the armpits and around the neck. Fan vigorously.

If they are unconscious, put them in the recovery position – on their side, head tilted back to keep the airway open, mouth pointing slightly down so any vomit can drain. Do not give fluids to anyone who is unconscious or vomiting. Stay with them. Watch their breathing. If they stop breathing and you are trained in CPR, begin immediately. The 999 call handler will talk you through it if you are not.

Heatstroke is one of those emergencies where fast, aggressive cooling genuinely saves lives. The British Red Cross UK first-aid guidance is clear on this: the sooner the body temperature comes down, the better the outcome.

Who is most at risk and needs checking on during the alert

Certain groups are more vulnerable to heat and need extra attention during an amber alert.

Adults aged 65 and over are at higher risk because the body regulates temperature less efficiently with age. This is especially true for those 85+, who may lose the ability to sweat as efficiently and often have reduced thirst sensation – they do not feel thirsty even when they are dehydrating. Babies and children under 5 have smaller bodies, a higher surface-area-to-volume ratio and less sweat capacity. Pregnant women face additional strain on the cardiovascular system. People with heart disease, kidney disease, diabetes, asthma or COPD are more vulnerable because heat puts extra demand on the heart, kidneys and lungs. People on certain medications – more on those below – may find their usual prescriptions reduce their ability to cope.

People who cannot move themselves easily, including bed-bound patients and those in upper-floor flats with poor air flow, are at particular risk. So are people who exercise outdoors at midday and people who are homeless or sleeping rough.

Phone or visit older relatives, neighbours and isolated friends at least once a day during an amber alert. Check curtains are closed on the sunny side, a fan is running, they have cool food and drink that does not need cooking. Check they are actually drinking. If they seem confused, unusually drowsy or unsteady on their feet – this can be heatstroke. Call 999.

How to keep your home cool during a UK heatwave

Keeping a UK home cool is largely about managing when air and sunlight come in. Most of it costs nothing.

Close curtains and blinds on the sunny side of the house during the day. That blocks radiant heat before it turns the room into a greenhouse. Open windows when the outside air is cooler than inside – typically before 8am and after 9pm. If you can create a cross-draught by opening windows on opposite sides of the house, do.

Use a fan, but know its limits. In temperatures above 35C, a fan blowing hot air may not cool you and can speed up dehydration through evaporation. To make a fan more effective, sit it in front of a bowl of ice or drape a damp sheet over a clothes airer in front of it for evaporative cooling.

Move downstairs to the coolest room or the ground floor if you can. Heat rises, and upstairs bedrooms – especially in older UK terraces and flats – can stay uncomfortable well into the night. A room thermometer costs a few pounds and is genuinely the single most useful tool for taking the guesswork out of all this.

Avoid using the oven during the day. Eat cool foods – salads, sandwiches, fruit. Leave tumble dryers and dishwashers for the evening. If you have a portable air conditioning unit, set it to 24-26C rather than blasting cold, which is less efficient and harder on the body when you step back outside.

How to keep your body cool and hydrated

The basics of keeping cool in a UK heatwave are well established and need no special kit.

Drink fluids regularly throughout the day, even before you feel thirsty. Aim for around 2.5-3 litres in a heatwave, more if you are exercising or sweating heavily. Plain water is the best general choice. Avoid alcohol, fizzy drinks and caffeine – all of which can drive fluid loss.

Wear loose, light-coloured clothing in cotton or linen. A wide-brimmed hat and UV-blocking sunglasses protect the face and eyes outdoors. Apply SPF 30 or higher sunscreen to all exposed skin every two hours and after swimming or sweating. Stay in the shade between 11am and 3pm, when UV is strongest and the air is hottest.

Take cool showers or baths. Use a damp flannel on the back of the neck and forearms – the carotid arteries in the neck and the radial arteries in the wrist are close to the surface and cool the blood efficiently.

For runners and cyclists training during the alert: do not overhydrate with plain water alone if you are out for more than an hour. Exercise-associated hyponatremia – dangerously low sodium from drinking too much plain water – is a real UK risk, especially in longer events on hot days. Warning signs include bloated stomach, puffy fingers, headache and confusion. Use an isotonic sports drink or oral rehydration sachet instead. Run early in the morning, before 7am if you can, and keep sessions short. Skip midday training entirely.

Medications and conditions that increase heat risk

Several common UK prescriptions reduce the body ability to cope with heat. That does not mean you should stop taking them – it means you need to plan more carefully.

Diuretics like furosemide and bendroflumethiazide, often called “water tablets,” increase fluid loss through urine. ACE inhibitors and angiotensin receptor blockers – ramipril, losartan, candesartan – affect how blood pressure responds when blood vessels dilate in the heat. Beta-blockers such as atenolol and bisoprolol reduce the heart rate response that helps the body cope during exertion. SGLT2 inhibitors used for diabetes and heart failure, including dapagliflozin and empagliflozin, can increase dehydration risk. Lithium levels can rise dangerously if you dehydrate, because the kidneys retain more of the drug. Antipsychotics, tricyclic antidepressants like amitriptyline and dosulepin, and older first-generation antihistamines such as chlorphenamine (Piriton) all reduce the body ability to sweat.

Do not stop any prescription medication without speaking to your GP first. If you take any of these, the response is: drink more fluids, spend more time in the shade, take cool showers, and make sure someone checks in on you daily.

Medication storage matters too. Insulin, Mounjaro and Wegovy pens should be kept in the fridge before first use and then stored below 25C, away from direct sunlight. Many UK kitchens, conservatories and south-facing windowsills exceed 25C during an amber alert. Move pens to a cooler interior cupboard or use an insulin cool case if you are travelling. GTN spray and salbutamol inhalers also lose effectiveness in extreme heat. Discard any medication that has been exposed to high temperatures and check the patient information leaflet.

Babies, young children and the chest-check during heatwaves

Babies and young children need particular care during hot weather because their bodies heat up faster and they cannot tell you how they feel.

Babies under 6 months should never be in direct sunlight. Use a parasol or a pram cover designed to allow air flow. Do not drape a thick blanket or muslin over the pram – it traps heat and can push the temperature inside the pram above the surrounding air. Apply SPF 30+ sunscreen to babies over 6 months.

Sleep is the area parents and carers worry about most. The Lullaby Trust safer-sleep guidance still applies in a heatwave: babies are safer cooler than too hot, ideal room temperature is 16-20C. In a bedroom above 24C, a short-sleeve vest or just a nappy is safe for sleep, with a 0.5 tog sleep bag or none at all. Check baby temperature using the Lullaby Trust method – feel the chest or the back of the neck. Hands and feet are normally cool and are not a reliable guide. Use a damp muslin cloth to cool the skin. Never wrap a baby in a cold wet towel – this can trigger shivering, which actually raises body temperature.

For hydration, offer extra breastfeeds for babies under 6 months who are exclusively breastfed. Older babies can have small amounts of cool water in addition to milk or formula. Watch for dehydration: fewer wet nappies than usual, a sunken fontanelle, drowsiness, sunken eyes, no tears when crying.

Never leave a child in a parked car, even for a moment. Internal temperatures rise to fatal levels within minutes, even with the windows partly open.

Frequently Asked Questions

What is the difference between a yellow, amber and red heat-health alert in the UK?

Yellow means vulnerable people are at increased risk and warrants targeted action by health and social care services. Amber means the whole population is at increased risk and the NHS will feel significant impact – more A&E attendances, more ambulance calls and possible cancellation of non-urgent operations. Red means significant risk to life even for healthy adults, and major disruption to NHS services. The 22-28 May 2026 alert was amber across most of England, covering tens of millions of people. Take an amber alert seriously even if you feel fine – the people around you may be more vulnerable than you think.

How do I tell if it is heat exhaustion or heatstroke?

Heat exhaustion causes tiredness, weakness, dizziness, headache, nausea, muscle cramps, fast breathing, pale clammy skin, thirst, dark urine and a temperature usually 38C or above. Most people improve within 30 minutes of cooling and fluids. Heatstroke means the person is still unwell after 30 minutes of cooling, has a temperature of 40C or above, has hot dry skin that is no longer sweating, and may show confusion, slurred speech, seizures or loss of consciousness. The clearest red flag is dry skin in someone who was sweating a few minutes ago. Heatstroke is a 999 emergency.

Can I still take my blood pressure tablets and water tablets during the heatwave?

Yes. Do not stop any prescription medication without speaking to your GP. Several common UK prescriptions – including diuretics, ACE inhibitors, beta-blockers, lithium, antipsychotics and older antihistamines – increase heat risk because they affect fluid balance, blood pressure response or sweating. The answer is not to stop them but to plan more carefully: drink more fluids, stay in the shade between 11am and 3pm, take cool showers and arrange for someone to check on you daily.

Should I store my Mounjaro or insulin differently during a UK heatwave?

Yes. Insulin and Mounjaro or Wegovy pens should be kept in the fridge before first use and then stored below 25C away from direct sunlight once in use. Many UK kitchens, conservatories and south-facing windowsills exceed 25C during an amber alert. Move pens to a cooler interior cupboard or use an insulin cool case for travel. Discard any pen that has been exposed to extreme heat, as high temperatures reduce effectiveness. Check the patient information leaflet for your specific product.

Is it safe for my baby to sleep in a hot bedroom during the heatwave?

Yes, with adjustments. The Lullaby Trust safer-sleep advice still applies: babies are safer cooler than too hot, recommended room temperature 16-20C. In a bedroom above 24C, a short-sleeve vest or just a nappy is safe, with a 0.5 tog sleep bag or none. Check your baby temperature by feeling the chest or back of the neck, not the hands or feet. Close curtains during the day, open windows after 9pm if outside is cooler, and use a fan in the room but not aimed directly at the baby.

I am a runner – can I still train in the morning during an amber alert?

Train early, before 7am if you can, and keep the session short. If you are out for more than an hour, drink an isotonic sports drink rather than plain water alone. Exercise-associated hyponatremia from overhydrating with plain water is a real UK risk, with bloated stomach, puffy fingers, headache and confusion as warning signs. Wear loose, light-coloured kit and a cap. Stop and seek shade if you feel dizzy or nauseous. Skip midday training – the risk is not worth it.

This article is informational only and does not replace personalised advice from your GP, pharmacist, or another qualified healthcare professional.