How to deal with heat rash and sunstroke

Whether you're enjoying a UK heatwave or escaping to a sunnier destination, spending time in high temperatures can increase your risk of sunburn, heat rash and more serious heat-related illnesses – if you're not prepared.

With increasingly unpredictable temperatures – and record highs in recent years – it's easy to get caught out.

As Dr Adrian Boyle, vice-president of the Royal College of Emergency Medicine, told us: 'We know that climate change is making our summers hotter, and society needs to acknowledge and be alert to the serious health risk that extreme heat presents.'

Here's what you can do to stay safe when things hot up.

Cheap sunscreens that work – we have some Great Value options that will protect your skin and feel nice to wear.

Stay safe in the heat

The best treatment is prevention, so be prepared. 

If you're heading to a sports event, festival or beach, or know that you'll be outside for much of the day, check the forecast and plan accordingly. Find ways to cover up and add in plenty of hydration stops. 

Dr Matthew Booker, St John Ambulance associate medical director, advises the following simple steps:

• Avoid the midday sun. Stay out of the sun at peak times, usually between 11am and 3pm, and seek shade instead. If it's unavoidable, such as if you're in a stadium or taking part in sporting activities, take plenty of breaks in the shade.
• Dress to protect yourself from the sun. Wear lightweight, light-coloured clothing plus sunglasses and a wide-brimmed hat to keep the sun off your face and neck.
• Keep well hydrated. Drink plenty of water or non-alcoholic fluids, little and often. Keep a water bottle close to hand to stay topped up. Insulated bottles will keep your water cool for longer – check out the best water bottles guide.
• Use sunscreen. This should be a minimum broad-spectrum SPF30, and should be regularly reapplied.

If the weather is particularly hot where you are for a sustained period, be sure to check in on any relatives or neighbours who may be more vulnerable to heat-related illnesses, ensuring they have ways to keep hydrated and cool.

At home, keeping curtains or blinds closed in sunny rooms during the day can help to keep the house cool. Switch to a simple bed sheet or summer duvet and wear light, breathable clothes.

Best handheld and neck fans 2026: portable fans to keep you cool.

Health? or Hype?

Make the right choice with recommendations you can trust, backed by expert testing.

Explore health recommendations

Heat rash: what it is and how to treat it

Heat rash (also known as prickly heat) is usually harmless, and should clear up on its own within a few days once you're out of the sun.

It occurs when sweat ducts become blocked, trapping sweat beneath the skin and causing tiny red spots, blisters or bumps. 

Treatment focuses on keeping cool and hydrated, staying away from excessive heat, and taking a cool bath or shower. Drinking lots of water and applying cool compresses or a cold pack wrapped in a towel may also help to soothe symptoms, as does wearing loose cotton clothing to allow body heat to escape.

A pharmacist or healthcare professional may suggest using calamine lotion, antihistamine tablets or hydrocortisone cream (not for under-10s or if you're pregnant) to relieve the itching. For more advice, see the NHS guide to heat rash.

It's worth taking stock of what skin products you've used if you get heat rash for the first time after using something new. Some alcohol-based clear sprays, for example, may aggravate or irritate skin.

How to manage sunburn 

If you've been caught out and got burned, here's what you should do:

1. Seek shade. Cover sunburnt skin and keep away from direct sunlight until healed.
2. Cool the skin down for 10 minutes. Use a damp towel or have a cool shower or bath (never ice or ice packs).
3. Drink cool water. Sunburn can contribute to fluid loss, so staying hydrated can help your body recover. 
4. Use aftersun or calamine lotion to soothe the burn. Look for ingredients like aloe vera and avoid moisturisers that contain alcohol. 
5. Take a painkiller. Paracetamol or ibuprofen can help if the burn is particularly painful. 
6. Know when to seek advice. Consult a pharmacist or doctor if the skin has blistered or swollen, or if you're feeling generally unwell. Always seek medical advice if your baby or young child has sunburn. Find out more in the NHS guide to sunburn.

Best sun creams – discover which sunscreens passed our independent sun safety tests in 2026.

Heat exhaustion vs heatstroke: how to treat it and how long it lasts

Sweating is the body's way of keeping us cool, but if we're out in the heat for long periods, the slow-but-sure loss of water and salts can lead to heat exhaustion. Untreated, this can lead to the more serious heatstroke (sunstroke), which requires prompt action.

Heat exhaustion symptoms

• Headache
• Dizziness and confusion
• Feeling or being sick
• Sweating with pale, clammy skin
• Cramps in arms, legs and stomach
• Fast breathing and rapid heartbeat.

If you have heat exhaustion, this doesn't usually need emergency medical help, as long as you can cool down within 30 minutes. 

Lie down in a cool place with your legs raised and drink water or an isotonic sports drink, and have someone keeping tabs on your breathing, pulse and responsiveness. If there's no improvement after 30 minutes, the NHS says to call 111 or 999.

Heatstroke symptoms

• Headache
• Dizziness and discomfort
• Restlessness and confusion
• Hot, flushed skin that might be dry or sweaty
• Rapid deterioration in responsiveness 
• A fast pulse and body temperature (often above 40°C/104°F).

If you think someone has heatstroke, NHS advice is to try to keep them cool and call 999. 

You can find out more on the NHS heatstroke advice page.

Symptoms of heatstroke in children are similar, but they may also be more irritable.

Best insect repellents – warmer weather means more biting bugs. We've uncovered the products that will keep you protected.

Who needs to take extra care when it's hot and sunny?

Some people need to take extra care with high temperatures, including children and older people. But there are other factors that can put you at risk, including the following:

Skin conditions: Exposure to sunlight or UV light can trigger a number of skin conditions, including sun allergy (solar urticaria), polymorphic light eruption, cold sores and rosacea. Seek advice for suitable medication, such as antihistamines or steroids, as well as using sun protection and minimising sun exposure.

Migraine and headaches: Dehydration can worsen these but a humid day and rising temperatures can also bring on head pain. The NHS says pressure changes are thought to be one factor that can trigger headaches in some people. 

Serious or long-term illness: People with conditions such as diabetes, kidney disease, asthma, heart disease, chronic obstructive pulmonary disease (COPD), epilepsy, multiple sclerosis and Parkinson's disease may find that their symptoms worsen in the heat, and Dr Boyle says people who are frail or suffering from dementia may be particularly at risk because they're less able to respond to their body's warning signs.

Mental illness: Researchers found there were more mental health emergencies on the hottest days. Dr Boyle says: 'People experiencing mental ill health – especially those taking antipsychotic medication – can be disproportionately affected by hot weather.'

Medications that cause sun sensitivity: Some medicines, including common antibiotics, oral contraceptives, steroid creams and antidepressants, can result in sunburn-like symptoms, a rash or other unwanted side effects. Professor Claire Anderson, president of the Royal Pharmaceutical Society, says: 'You can reduce your risk of photosensitivity by staying out of direct sunlight, protecting yourself with a high-factor sunscreen, and covering up with long sleeves, trousers and a hat.'

6 surprising foods and drinks that could affect your medication.