Who this guidance is for
This guidance is from the UK government and provides advice for everyone on how to stay safe during hot weather.
Anyone can become unwell if they get too hot. However, some people are at higher risk of becoming seriously unwell.
It is important to follow this guidance so that you are prepared for hot weather and can take action to cool yourself and your home.
Actions you can take to stay safe in hot weather
While many people enjoy warmer summer weather, hot weather can cause some people to become unwell through overheating (becoming uncomfortably hot), dehydration, heat exhaustion and heatstroke.
- if you are going to do a physical activity (for example exercise or walking the dog), plan to do these during times of the day when it is cooler such as the early morning or the evening
- keep your home cool by closing windows and curtains in rooms that face the sun
- drink plenty of fluids and limit your alcohol intake
- check on family, friends and neighbours who may be at higher risk of becoming unwell, and if you are at higher risk, ask them to do the same for you
- know the symptoms of heat exhaustion and heatstroke and what to do if you or someone else has them
- Try to avoid direct sunlight, especially between 11am and 3pm when UV levels are highest
- If you are going out during this time, cover up with suitable clothing, wear a wide-brimmed hat and sunglasses, seek shade and apply sunscreen liberally and re-apply frequently
About hot weather and health
Climate change is already causing warmer temperatures in the UK. All of the warmest years on record in the UK have occurred since 2002, and in July 2022 temperatures exceeded 40°C for the first time on record. It is estimated that 2,803 people aged 65 years and over died due to the heat in England in 2022, and it is predicted that the number of heat-related deaths per year may triple by 2050.
Hot weather can increase the risk of heart attack, stroke, lung problems and other diseases. Older people, babies and young children are more likely to be unwell from hot weather because their bodies are less able to regulate temperature. People with underlying medical conditions can also be vulnerable to the effects of hot weather.
Many of the harms linked to heat exposure are preventable if a few simple actions are taken. During the summer, UKHSA will work with the Met Office to issue alerts alongside the weather forecast if the weather is so hot that it has the potential to affect people’s health, and will help you to take steps to protect yourself and others.
People at higher risk of becoming unwell in hot weather
Anyone can become unwell when the weather is hot. People who are at higher risk of becoming seriously unwell include:
- older people aged 65 years and over (note change from previous guidance of 75 years of age and above)
- babies and young children aged 5 years and under
- people with underlying health conditions particularly heart problems, breathing problems, dementia, diabetes, kidney disease, Parkinson’s disease, or mobility problems
- pregnant women
- people on certain medications
- people with serious mental health problems
- people who are already ill and dehydrated (for example from diarrhoea and vomiting)
- people who experience alcohol or drug dependence
- people who are physically active and spend a lot of time outside such as runners, cyclists and walkers
- people who work in jobs that require manual labour or extensive time outside
- people experiencing homelessness, including rough sleepers and those who are unable to make adaptations to their living accommodation such as sofa surfers or living in hostels.
- people who live alone and may be unable to care for themselves
You should continue taking all of your prescribed medicines unless advised not to by a medical professional. If you have any health concerns, please call NHS 111. Some medications need to be stored below 25°C or in the fridge, following the storage instructions on the packaging.
Check in with anyone you think might be at risk and see if they need help.
Heat exhaustion and heatstroke
Heat exhaustion occurs when the body overheats and cannot cool down. Heat exhaustion does not usually need emergency medical attention if you cool down within 30 minutes. If you do not take action to cool down, heat exhaustion can lead to heatstroke.
Common symptoms of heat exhaustion include:
- tiredness
- weakness
- feeling faint
- headache
- muscle cramps
- feeling or being sick
- heavy sweating
- intense thirst
Heatstroke is where the body is no longer able to cool down and the body temperature becomes dangerously high.
Common symptoms of heatstroke include:
- confusion
- lack of co-ordination
- fast heartbeat
- fast breathing or shortness of breath
- hot skin that is not sweating
- seizures
Heatstroke is a medical emergency. If you think someone has heatstroke you should dial 999 and then try to cool them down.
You can find out more about symptoms of heat exhaustion and heatstroke on NHS.UK.
How to cool down
How to cool down if you or someone else has symptoms of heat exhaustion:
- move to a cooler place such as a room with air conditioning or somewhere in the shade, avoid direct sunlight
- remove all unnecessary clothing like a jacket or socks
- drink cool water, a sports or rehydration drink, or eat cold and water rich foods like ice-lollies
- apply cool water by spray or sponge to exposed skin, and using cold packs wrapped in a cloth and put under the armpits or on the neck can also help
You should start to cool down and feel better within 30 minutes.
If you are concerned about symptoms, or they are worsening, seek medical advice by contacting NHS 111. In an emergency, or if you think someone has heatstroke, dial 999.
Be prepared for hot weather
It is important to follow the advice in this guidance to be prepared for hot weather. This is particularly important if you are higher risk of becoming seriously unwell. To prepare, you can:
- listen to the news and check your local weather forecast so that you know when hot weather is expected
- when hot weather is expected, plan your activities for early morning or the evening, when it is usually cooler
- look out for advice on what to do if services such as power, water supplies and transport are likely to be affected
- check air pollution forecasts and advice, as air pollution can become worse during hot weather and can cause problems for people with asthma and other breathing problems
Stay well when there is hot weather
There are things you can do to prevent yourself from overheating when the weather is hot. If you do get too hot, it is important to give your body a break from the heat and take actions that will help cool you down.
Prevent dehydration
Drink fluids regularly throughout the day especially if you are physically active. You should drink enough that your pee is a pale straw colour.
Water and diluted squash or lower fat milks are good choices. Fruit juice, smoothies and soft drinks can be high in sugar which dehydrates the body. Limit the amount of fruit juice or smoothies that you drink, and swap sugary soft drinks for diet, sugar-free or no added sugar varieties.
If you are going out, take a refillable bottle filled with water. Take extra water for journeys on public transport or by car.
Alcohol has a dehydrating effect on the body, so it is a good idea to choose alcohol-free options, or alternate alcoholic drinks with a glass of water.
If you are fasting during a heatwave, it is important to drink enough to adequately hydrate before you fast and follow the guidance on keeping cool and preventing dehydration. People with underlying health conditions should seek medical advice before fasting.
You can find more information on the signs and symptoms of dehydration on NHS.UK.
Protect yourself from the sun
The sun is often strong enough in the UK to cause sunburn even when it is cloudy. Babies and children’s skin is more sensitive and are particularly at risk of skin damage from the sun.
Take the following actions to protect yourself from the sun:
- try to stay in the shade, between 11am and 3pm when UV levels are highest
- wear lightweight, loose-fitting, light-coloured clothes, such as a long-sleeved shirt, trousers, or long skirts in close-weave fabrics
- wear a wide-brimmed hat to protect your face, eyes, head, ears, and neck
- wear sunglasses which are wraparound or with wide arms to provide protection from the sun
- apply sunscreen generously and re-apply frequently, especially after activities that remove it, such as swimming or towelling. The NHS recommends that this should be with a sun protection factor (SPF) of at least 30, and 4 or 5 star ultraviolet A (UVA) protection
You can find more information on sunscreen and sun safety, including how to apply sunscreen, on NHS.UK.
Limit strenuous physical activity
If you can, limit the amount of strenuous physical activity that you do during the hottest part of the day. Check weather forecasts to see when it will be cooler. Where possible, plan to do physical activities during the early morning or in the evening, when it is usually cooler.
Children should not take part in strenuous physical activities on very hot days.
Avoid hot closed spaces
Small, closed spaces such as stationary cars can get dangerously hot very quickly. Make sure that babies, children, older people and pets are not left alone in stationary cars or other closed spaces.
Ensure children in prams or pushchairs are shaded by using a parasol. Make sure there is adequate air flow, remove any excess clothing and check on them regularly to make sure they are not overheated. You can find more information on keeping your baby safe in the sun on NHS.UK.
Keep your home cool
Homes can overheat and become uncomfortable during warmer weather, particularly when you are trying to sleep. Take the following steps to cool your home:
- close blinds and curtains on windows that are exposed to direct sunlight during the day
- close external shutters or shades if you have them
- move to a cooler part of the house, especially for sleeping
- open windows (if it is safe to) when the air feels cooler outside than inside, for example at night, and try to get air flowing through your home
- use electric fans if the air temperature is below 35°C, but do not aim the fan directly at your body as this can lead to dehydration
- check that any heating is turned off
- turn off lights and electrical equipment that are not in use
- go outside if it is cooler outside in the shade
Public buildings such as places of worship, local libraries or supermarkets may be cooler than your home. If they are nearby consider visiting one of these as a way of cooling down.
Stay safe when swimming
Swimming pools, rivers, lakes, or the sea can be a fun way to cool down when the weather is hot, however summer months are also associated with an increase in drowning accidents.
The following advice can help to keep you safe when swimming:
- always look for warning and guidance signs
- only enter the water in areas with lifeguard cover
- never enter the water after drinking alcohol
- wear a buoyancy aid or life jacket if you are doing an activity out on the water or at the water’s edge such as boating or fishing
- be aware that open water can be much colder than it looks which can lead to cold water shock
- get out of the water as soon as you start to feel cold
- swim parallel with the shore, not away from it
- always go swimming with someone else so you can help each other out
- check Swimfo to look up details of a designated bathing water quality by name or location
- take extra care to protect yourself from UV when swimming, when the cooling effect of the water may provide a false sense of safety and UV levels are stronger due to surface reflections. Cover as much skin as possible, apply water resistant sunscreen and re-apply regularly.
You can find more information on safe summer swimming from the Royal Life Saving Society (RLSS).
More information and support
It is important to remember to take care of your mind as well as your body and to get support if you need it. There are sources of support and information that can help. Every Mind Matters provides a lot of useful information.
Your local council can provide advice if you are concerned about a friend, neighbour or family member who needs additional support.