Keeping cool in a heatwave without air conditioning

Official advice first

Most UK homes have no air conditioning, and the official advice doesn't assume you have it. UKHSA's Beat the Heat guidance, the NHS and GOV.UK Be Ready all give the same core steps: keep the sun out by day, let cooler air in when it's cooler outside, and look after the people most at risk.

Watch for Met Office warnings and, in England, UKHSA Heat-Health Alerts (yellow, amber or red). The main alert season runs from 1 June to 30 September, but alerts can be issued outside it. The alerts are free to view, and you can sign up for emails (UKHSA).

Step 1: Keep the sun out during the day

• Close curtains and blinds on windows that get direct sun. Close outside shutters if you have them (UKHSA).
• Turn the heating off and check it stays off (UKHSA, Be Ready).
• Turn off lights and electrical equipment you're not using, and cook at cooler times of day (UKHSA checklist).
• For the longer term, Be Ready suggests external shutters, awnings, internal blinds, or outdoor plants to shade south-facing windows.

Step 2: Let cooler air in when it's cooler outside

• Open windows when the air outside feels cooler than inside, usually in the evening and at night, to get air moving through the home. Only do this when it's safe (UKHSA, NHS).
• If your home has a ventilation system, UKHSA says check it's on and set to summer mode.
• Our own advice, not from the official pages: keep window restrictors and child safety catches in place. Security and child safety come before airflow.

Step 3: Fans, water and the coolest room

• Electric fans help when the air is below 35°C. Don't point a fan straight at your body: UKHSA says this can lead to dehydration.
• Move to the coolest part of the home, especially to sleep (UKHSA).
• Drink plenty, and avoid alcohol, caffeine and hot drinks (NHS). If the power or water is off, the Chief Medical Officers say aim for at least 2 litres of liquid a day.
• Keep out of the sun between 11am and 3pm (NHS, Be Ready).
• If your home stays too hot, go somewhere cooler, such as a library or supermarket, if you can travel safely (UKHSA).

Is your home likely to overheat?

UKHSA lists homes that tend to get hotter than others. If yours is one of them, start on Step 1 early in the day:

• top-floor flats
• homes with windows on only one side
• homes with little shade, or large unshaded windows facing east, west or south
• built-up areas with little green space
• very well insulated homes, which can trap heat
• homes where windows can only open a little

Who is most at risk

UKHSA and the NHS say these people are at higher risk in hot weather:

• people aged 65 and over
• babies and children aged 5 and under
• pregnant women
• people with heart or breathing problems, dementia, diabetes, kidney disease, Parkinson's or mobility problems
• people on several medicines, or on medicines that make heat harder to cope with
• people who live alone, or who are homeless
• people who work or exercise outdoors

Check on family, friends and neighbours who may be at risk, and ask someone to check on you if you are (UKHSA). Your local council can advise if you're worried about someone who needs extra support.

Medicines in the heat

• Keep taking prescribed medicines unless a health professional tells you otherwise (UKHSA).
• Some medicines must be kept below 25°C or in a fridge. Follow the packaging (UKHSA).
• If you're unsure, ask your pharmacist or call NHS 111.
• For what to keep at home, see our home medicine cabinet list.

Heat exhaustion and heatstroke

The NHS lists the signs of heat exhaustion: tiredness, dizziness, headache, feeling or being sick, heavy sweating, pale clammy skin, cramps, a high temperature, strong thirst and irritability.

What to do (NHS): move the person somewhere cool, remove extra clothing, give plenty to drink, and cool their skin with cool water and a fan. They should feel better within 30 minutes.

Call 999 if they're still unwell after 30 minutes, or if they have a very high temperature, hot skin that isn't sweating, fast breathing or heartbeat, confusion, a fit or loss of consciousness. Heatstroke is a medical emergency (NHS).

Pets and cars

• Never leave babies, children, older people or pets in a parked car. Small, closed spaces get dangerously hot quickly (Be Ready).
• Walk dogs at cooler times, such as early morning or evening (Be Ready).

What we couldn't find official advice on

• Portable air conditioners: no UK official recommendation either way.
• Terracotta pot coolers, ice in front of fans and similar tricks: no official UK guidance, and we found no good evidence. We don't recommend spending money on them.
• A safe indoor temperature target: UKHSA's guidance doesn't give one. It focuses on the 35°C fan limit and on comparing indoor and outdoor air.

See also our storm, flood and heatwave checklists, which you can print.

Related guides

• Heatwave at home: keeping your home and people cool and safe
• Extreme weather in the UK: heatwaves, storms, floods and wildfires
• Medicines that need a fridge: what to do in a power cut

Free tools

• Storm tracker: live Met Office warnings
• Power cuts, floods and weather warnings near me

We're an independent UK site, not the government. We check guides against official sources and link to them. In an emergency call 999.

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