How to Keep Cool During a Power Cut in Hot Weather

A power cut in hot weather takes away the two things most households rely on to stay comfortable: fans and air conditioning. The first thing to do is simple and needs no electricity at all. Put on light, loose-fitting cotton clothing, covering as much of the skin as possible, and drink extra cold fluids while avoiding alcohol, caffeine and hot drinks¹. Then shut the heat out of the rooms you are using, and open them up again once the air outside is cooler.

The second thing is to know who around you is most at risk. Older people, those with underlying health conditions and those who live alone are particularly vulnerable when it is hot, and a power cut removes the fans and cooling they may depend on³. Check on them early, and again through the day.

The third is to know where information and help will come from. The power cut helpline is 105, and it is worth having that number somewhere you can find it without a phone screen⁴. Heat-Health Alerts, issued by the UK Health Security Agency, tell you how serious the hot weather is expected to be, and you can check them before and during an outage⁵.

Stay cool without power: what to wear and drink

Clothing does most of the work when the power is off. Official advice is to wear light, loose-fitting cotton clothes, covering as much of the skin as possible¹. Loose cotton lets air move against the skin and does not trap heat the way synthetic fabrics can. If you go outdoors, add a hat and sunglasses⁸. The point is not fashion but body temperature: without a fan or air conditioning, what you wear is the main thing regulating how hot you feel.

Drinking matters just as much. Have cold food and regular cold drinks, drink extra fluids, and avoid alcohol, caffeine and hot drinks, which can dehydrate you². The fire and rescue service gives the same message in its hot weather safety advice: drink plenty of fluids, water if possible, and avoid alcohol, tea and coffee⁹. Keep a jug or bottles of water where you are sitting rather than in a kitchen you have to keep getting up to visit.

If you must be active, move it. Avoid strenuous activity during the hottest part of the day and plan activities for cooler times like early morning or evening¹⁰. If you cannot avoid outdoor work such as gardening or DIY, keep it for the cooler parts of the day, stay in the shade, and take plenty of water¹¹. Heat exhaustion builds quietly; pacing yourself is part of staying well.

Keep your home cool by shutting out the heat

The principle is to keep the heat outside while it is hotter outdoors, and let cooler air in when the day turns. Close the curtains in rooms that face the sun and make sure there is plenty of ventilation⁷. Shut windows and pull down the shades when it is hotter outside; if it is safe, open them for ventilation when it is cooler¹². Keep windows that are exposed to the sun closed during the day, and open windows at night when the temperature has dropped⁷.

Shading from outside works better than shading from inside. Keep rooms cool by using shades or reflective material outside the windows; if that is not possible, use light-coloured curtains and keep them closed, because metallic blinds and dark curtains can make the room hotter¹¹. Closing curtains or blinds, or shading windows, is the standard advice for keeping a home cool¹³.

A few household checks help too. Check that your heating is turned off¹⁴. Turn off any appliances you do not need, and check that your fridge and freezer are working properly⁷. During a power cut, keep fridge and freezer doors closed to protect the temperature inside¹⁵. If you have a fan that runs on batteries, use it to cool the room down, but do not rely on it: the power may be out for hours.

Check for a heat health alert before and during a power cut

Heat-Health Alerts are the official signal of how dangerous the hot weather is expected to be. The service runs from green, when no alert is issued because conditions are likely to have minimal impact on health, upwards when hot weather is likely to affect health⁵. Alerts are published by the UK Health Security Agency, and you can check the current level for your area before and during a power cut⁵.

The general advice attached to heat health alerts is to stay hydrated, avoid the hottest part of the day, keep indoor spaces cool where possible, and check on vulnerable people¹⁰. Listen to alerts on the radio, TV and social media about keeping cool¹⁶. With the power off, a battery or wind-up radio is more useful than a phone you are trying to conserve.

The levels are explained in more detail on our page on Heat-Health Alerts: Yellow, Amber and Red Explained, and you can find out how to receive them on How to Sign Up for Heat-Health Alerts. If you are unsure whether an alert is in force, treat hot weather with the same care anyway: the basic actions, shade, fluids and checking on others, do not depend on the alert level.

Who is most at risk when it is hot and the power is off

Some people struggle to keep themselves cool and hydrated, and a power cut makes that harder. Older people, those with underlying health conditions and those who live alone are particularly at risk³. The Met Office adds that this includes people who cannot adapt their behaviour to keep cool, and those exposed to high levels of heat because of where they live or work¹⁷. Babies and young children, the bed bound, and people with drug or alcohol addictions may also find it hard to keep cool¹⁸.

A power cut adds a second layer of risk. Older adults, babies and young children, and people with long-term health problems are most likely to become ill if they get too cold during an outage, which is the mirror image of the heat risk and a reminder that the same households need checking on in either extreme¹⁹. If someone in your household depends on electrical equipment for their health, plan for what happens when it stops, and tell your electricity network operator in advance.

• Older people: may not feel thirsty and may not notice rising heat³
• People with underlying health conditions: more likely to become unwell in heat³
• People living alone: no one to notice if they deteriorate³
• Babies and young children: find it hard to keep cool¹⁸
• Bed bound people: cannot move to a cooler room¹⁸

Our page on Who Is Most at Risk in Hot Weather goes into more detail, and How to Check On Older and Vulnerable Neighbours in the Heat sets out what a useful check looks like.

Cool showers, damp cloths and getting through the night

When the power is off, water is your cooling system. Have a cool shower or put cool water on your skin or clothes². A damp cloth on the wrists or the back of the neck does the same job when a shower is not practical. Do not make the water painfully cold, especially for someone who is already unwell; the aim is to cool gradually.

Nights are the hardest part of a hot power cut, because the bedroom holds the day's heat and a fan is not available. At night, keep your sleeping area well ventilated; night cooling is important as it allows the body to recuperate¹⁷. Open the windows once the outside air is cooler than the room, and keep the curtains or blinds closed through the day so less heat builds up⁷. Light, loose cotton bedding helps, and so does a cool shower before bed.

If you have a battery fan or power bank, charge it before an expected outage and use it sparingly at night. Our pages on How to Sleep and Cool a Bedroom on Hot Nights and Cordless Rechargeable Fan or Mains Fan cover the detail. For the wider question of what to have ready before an outage, see Power Cuts: A Household Guide.

Where to get help during a power cut in hot weather

Start with your electricity network operator. Depending on where you live, you can get information about power cuts from the websites of National Grid (formerly Western Power) or Scottish and Southern Electricity Network²⁰. The power cut helpline number is 105, and it is worth having it somewhere accessible⁴. If it is a localised power cut, you may be able to stay with friends or relatives until your power is back on²¹.

Check whether your neighbours have power too. If they have power and you do not, your trip switch may have activated²². Leave a light on so you know when your power comes back, switch off appliances that could pose a hazard, keep a mobile phone charged, and write down important phone numbers²¹. If you are anxious, tell a friend or neighbour, and check on vulnerable neighbours or family¹⁵.

If someone becomes seriously unwell in the heat, cool them down as quickly as possible using whatever is available: water, ice packs, a fan, or a cool wet sheet, while you wait for help¹⁰. Our page on When to Call 999 or NHS 111 for Heat Illness sets out the warning signs, and Heat Exhaustion and Heatstroke: Signs and What to Do explains what to look for.