Guide to staying cool and safe in hot weather

As our climate changes, we are likely to experience more of these sudden and intense heatwaves when temperatures can reach the high 30s (C)/90s (F) and potentially into the 40s (C)/100s (F). Knowing the forecast can help you plan ahead and adapt as necessary.

Being prepared, knowing the signs of heat exhaustion and heat stroke to watch out for and staying hydrated are key actions to take, as well as looking out for neighbours and friends who may be vulnerable or unable to keep cool themselves.

High temperatures can be harmful to your health and can sadly lead to death, as some people run a greater risk of serious harm when the temperatures soar. Air pollution can also become worse during periods of hot weather.

Look out for signs of dehydration such as increased thirst, a dry mouth, dark urine, and urinating infrequently or small amounts. Serious dehydration needs urgent medical attention.

This guide gives you some handy tips on how to stay safe in hot weather, including how to keep your home cool. There’s also information on how to recognise when you or someone else is at risk of ill health due to the heat and steps you can take to help.

Drink plenty of fluids

Everyone is at risk of dehydration in hot temperatures, but babies, children and the elderly are particularly vulnerable. Check regularly for signs of dehydration or heat exhaustion.

Fluid requirements are higher than normal in hot weather and after strenuous activity it’s essential to replace fluids lost through sweating.

Drink cool water regularly throughout the day.

Fruit juice, smoothies and soft drinks do count towards your fluid intake but can be high in sugar. Limit fruit juice or smoothies to a combined total of 150ml a day and swap sugary soft drinks for diet, sugar-free or no added sugar varieties.

Look out for signs of dehydration such as increased thirst, a dry mouth, dark urine, and urinating infrequently or small amounts. Serious dehydration needs urgent medical attention.

Support others

Remember lots of public buildings (such as places of worship, local libraries or supermarkets) can be cool in summer; consider a visit as a way of cooling down.

How to reduce risk of heat exhaustion

It sounds obvious, but make sure the heating is off, stay out of the heat, cool yourself down, keep your environment cool or find somewhere else that is cool.

Get medical advice if you are suffering from a chronic medical condition or taking multiple medications.

Make sure medicines are stored below 25°C or in the fridge (read the storage instructions on the packaging). Carry on taking all prescribed medicines unless advised not to by a medical professional. But be aware that some prescription medicines can reduce your tolerance of heat.

Be alert and if someone is unwell, see the resources section at the end of this guide for how you can help.

Keep hydrated! Plain cool water is the best thing to drink – little and often.

Slow down. Cool your skin with cool water. Drink cool water.

Keeping children safe in hot weather

Children cannot control their body temperature as efficiently as adults during hot weather, because they do not sweat as much and so can be at risk of ill-health from heat. Heat-related illness can range from mild heat stress to potentially life-threatening heatstroke. The main risk from heat is dehydration. Teachers, assistants, school nurses and all child carers should look out for signs of heat stress, heat exhaustion and heatstroke.

Heat stress

Children suffering from heat stress may seem out of character or show signs of discomfort and irritability (including those listed below for heat exhaustion). These signs will worsen with physical activity and if left untreated can lead to heat exhaustion or heatstroke.

Heat exhaustion

Symptoms of heat exhaustion vary but include one or more of the following:

  • tiredness
  • dizziness
  • headache
  • nausea
  • vomiting
  • hot, red and dry skin
  • confusion

When the body is exposed to very high temperatures, the mechanism that controls body temperature may stop working. Heatstroke can develop if heat stress or heat exhaustion is left untreated, but it can also occur suddenly and without warning. Symptoms may include:

  • high body temperature – a temperature of or above 40°C (104°F) is a major sign of heatstroke
  • red, hot skin and sweating that then suddenly stops
  • fast heartbeat
  • fast, shallow breathing
  • confusion/lack of co-ordination
  • fits
  • loss of consciousness
Actions to protect children suffering heat illness

The following steps to reduce body temperature should be taken immediately:

  • move the child to as cool a room as possible and encourage them to drink cool water (such as water from a cold tap)
  • cool the child as rapidly as possible, using whatever methods you can. For example, sponge or spray the child with cool (25 to 30°C) water – if available, place cold packs around the neck and armpits, or wrap the child in a cool, wet sheet and assist cooling with a fan
  • dial 999 to request an ambulance if the child doesn’t respond to the above treatment within 30 minutes

If a child loses consciousness, or has a fit, place the child in the recovery position, call 999 immediately and follow the steps above until medical assistance arrives.

Protecting children outdoors

During periods of high temperature, the following steps should be taken:

  • children should not take part in vigorous physical activity on very hot days, such as when temperatures are higher than 30°C
  • encourage children playing outdoors to stay in the shade as much as possible
  • children should wear loose, light-coloured clothing to help keep cool and sunhats with wide brims to avoid sunburn
  • use sunscreen (at least factor 15 with UVA protection) to protect skin if children are playing or taking lessons outdoors for more than 20 minutes
  • provide children with plenty of water (such as water from a cold tap) and encourage them to drink more than usual when conditions are hot
Protecting children indoors

During periods of high temperature, the following steps should be taken:

  • open windows as early as possible in the morning before children arrive, or preferably overnight to allow stored heat to escape from the building – it is important to check insurance conditions and the need for security if windows are to be left open overnight
  • almost close windows when the outdoor air becomes warmer than the air indoors – this should help keep the heat out while allowing adequate ventilation
  • use outdoor sun awnings if available, or close indoor blinds or curtains, but do not let them block window ventilation
  • keep the use of electric lighting to a minimum
  • switch off all electrical equipment, including computers, monitors and printers when not in use – equipment should not be left in ‘standby mode’ as this generates heat
  • if possible, use those classrooms or other spaces which are less likely to overheat, and adjust the layout of teaching spaces to avoid direct sunlight on children
  • oscillating mechanical fans can be used to increase air movement if temperatures are below 35°C – at temperatures above 35°C fans may not prevent heat-related illness and may worsen dehydration
  • if necessary, consider rearranging school start, finish, and play times to avoid teaching during very hot conditions
  • encourage children to eat normally and drink plenty of cool water

For further information on reducing temperatures within school buildings and grounds see UK Health Security Agency’s (UKHSA) Heatwave Plan for England.

Tips for keeping your home cool

Even during a relatively cool summer, 1 in 5 homes are likely to overheat. For many people, this makes life uncomfortable and sleeping difficult and, for the particularly vulnerable, a hot home can worsen existing health conditions and even lead to fatality.

Use our simple checklist to find out if your home is at risk of overheating and what you can do if there is a problem. You can view and download the checklist here.

Make sure you supervise babies, toddlers and young children around balconies or open windows to avoid the risk of falls.

Shade or cover windows exposed to direct sunlight: metallic blinds and dark curtains can make a room hotter.

Let the warm air out to cool the home, then keep the hot air out as the day heats up. You can do this by opening windows when the air feels cooler outside than inside, early in the morning and late at night. Remember to close curtains and windows again to keep the cool air trapped inside and the hot air outside.

Turn off lights and electrical equipment that aren’t in use.

If you have concerns about an uncomfortably hot home that is affecting your health or someone
else’s health, seek medical advice.

Make sure you supervise babies, toddlers and young children around balconies or open windows to avoid the risk of falls.

Signs of heat-related illness

Chronic illnesses can get worse in hot weather. Heat exhaustion and heatstroke are two potentially serious conditions that can occur if you get too hot. If heat exhaustion isn’t spotted and treated early on, there’s a risk it could lead to heatstroke. Severe heat exhaustion or heatstroke requires hospital treatment. Untreated heatstroke can be fatal.

Heat exhaustion

Heat exhaustion is where you become very hot and start to lose water or salt from your body. Common symptoms include weakness, feeling faint, headache, muscle cramps, feeling sick, heavy sweating and intense thirst.


Heatstroke is where the body is no longer able to cool itself and a person’s body temperature becomes dangerously high. Heatstroke is less common but more serious. Untreated symptoms include confusion, seizures and loss of consciousness.

What you can do

If you notice that someone has signs of heat-related illness, you should:

  • get them to lie down in a cool place – such as a room with air conditioning or a fan, or somewhere in the shade
  • remove any unnecessary clothing to expose as much of their skin as possible
  • cool their skin with cool water; you could use a cool wet sponge or flannel, cool water spray, cold packs around the neck and armpits, or wrap them in a cool, wet sheet
  • fan their skin while it’s moist – this will help the water to evaporate, which will help their skin cool down – an electric fan could be helpful to create an air current if the temperature is below 35°C, but fans can cause excess dehydration so they should not be aimed directly on the body and will not be enough to keep someone cool at temperatures above 35°C
  • get them to drink fluids – ideally water, lower fat milks, or a rehydration treatment
  • do not give them aspirin or paracetamol – this can put the body under more strain. They should carry on taking all other prescribed medicines unless advised not to by a medical professional
  • stay with the person until they’re feeling better. Most people should start to recover within 30 minutes
What to do when it’s an emergency

If a person has improved with the cooling advice above but you still have concerns about them, contact your GP or NHS 111 for advice.

You should call 999 for an ambulance if the person:

  • doesn’t respond to the above cooling treatments within 30 minutes
  • has severe symptoms, such as a loss of consciousness, confusion or seizures

If the person is unconscious, you should place them in the recovery position until help arrives. If they have a seizure, move nearby objects out of the way to prevent injury. You can find out more on NHS Choices.

Dress appropriately for the weather

Dressing appropriately can protect you from the sun’s radiation and keep you cool to prevent
heat-related illness. Children are particularly at risk of skin damage from the sun.

What you can do

If you have to go out in the heat, walk in the shade and wear lightweight, loose-fitting, lightcoloured cotton or linen clothes.

Wear suitable headwear, such as a wide-brimmed hat, to reduce exposure to the face, eyes, head and neck.

When exposed to direct sunlight, cover your skin with clothing that gives good protection; examples are long-sleeved shirts and loose clothing with a close weave. At home wear as little clothing as necessary.

Sunglasses should exclude both direct and peripheral exposure of the eyes to ultraviolet (UV) radiation, so a wraparound design is best.

Apply sunblock, or broad-spectrum sunscreens, with high sun protection factor (SPF) of at least SPF 15 with UVA protection regularly to exposed skin.

Slow down when it’s hot

It’s important during hot weather to moderate the way we live our lives by doing what we can to slow down, take breaks, stay cool indoors or in shade outdoors.

What you can do

Avoid extreme physical exertion. If you can’t avoid strenuous outdoor activity, such as sport, DIY or gardening, keep it for cooler parts of the day – for example, in the early morning or evening.

Children should not take part in vigorous physical activity on very hot days, such as when temperatures are above 30°C.

Cars get hot, avoid closed spaces

Small, closed spaces, such as cars, can get dangerously hot very quickly.

Some people, especially babies, young children and older people find it harder to stay cool. They may not be able to move themselves to a cool place if they are dependent on others.

What you can do

Ensure that babies, children or older people are not left alone in stationary cars or other closed spaces.

Look out for children in prams or pushchairs in hot weather; keep them in the shade, remove excess clothing, ensure there is adequate air flow, check regularly to ensure they are not overheated, and keep them hydrated.

For more information about how to identify if a baby/child is overheated, visit NHS Choices.

Stay safe when swimming

During hot weather cooling off in swimming pools or bodies of water such as rivers, lakes or the sea can provide great relief from the heat. But people who do not take the right precautions may find themselves in difficult, dangerous and sometimes life-threatening situations.

If someone is in difficulty in the water shout reassurance to them, shout for help and contact the emergency services (call 999 or 112).

Simple principles you should follow when swimming
  • always look for warning and guidance signs nearby
  • only enter the water in areas with adequate supervision and rescue cover
  • always wear a buoyancy aid or lifejacket for activities on the water or at the water’s edge (such as when boating or fishing)
  • never enter the water after consuming alcohol
  • be aware of underwater hazards
  • get out of the water as soon as you start to feel cold
  • swim parallel with the shore, not away from it
  • avoid drifting in the currents
  • do not enter fast flowing water always take someone with you when you go into or near water. If something goes wrong, they will be able to get help
  • if someone is in difficulty in the water shout reassurance to them, shout for help and contact the emergency services (call 999 or 112)

Supervise children around water

Young children can drown in less than two inches (six centimetres) of water, in only 20 seconds. If they are very young, you might not even hear them.

What you can do

Babies and infants need constant supervision around water – whether this is in the bath, paddling or swimming pool, or by the sea, ponds, rivers or lakes. Here are some simple guidelines to help parents and carers keep babies and children safe around water:

  • don’t get distracted by your mobile phone; don’t leave them unsupervised even for a moment
  • cover garden ponds or ensure they are fenced off securely. Always stay with your child if they are using a paddling pool and empty it after use
  • when near swimming pools (at home or on holiday) make sure you never leave your child unattended. This is still important if they are using swimming aids like arm bands, rubber rings or floats
  • teach children about water safety so that they choose safe places to swim, such as public pools and beaches patrolled by lifeguards, rather than canals, gravel pits and rivers, as these can be dangerous
  • make sure children wear appropriate, well-fitting life jackets if doing water sports

More information