Heatwaves in the United Kingdom are becoming longer, hotter and more frequent, and our housing was never designed to cope with them. Brick homes with small windows hold onto warmth for days, and many people are caught out because they assume British summers are always mild. A little preparation before the temperature climbs makes the difference between a manageable few days and a genuine health emergency, especially for those most at risk.
Understanding Met Office heat-health alerts
The Met Office and UK Health Security Agency run a Heat-Health Alert system that warns when high temperatures could affect health. Alerts are colour-coded: yellow signals a risk mainly for vulnerable groups, amber means impacts are likely across health and social care and possibly the wider population, and red indicates a serious risk to everyone, not just those who are unwell. Sign up for alerts or check the Met Office website when hot weather is forecast, and treat an amber or red warning as your cue to act rather than wait.
Use the days of warning to plan. Check on elderly neighbours or relatives, make sure you have enough of any regular medicines, and know where the coolest room in your home is. Preparing early is far easier than trying to cope once the heat has already built up indoors and everyone is tired and dehydrated.
Preparing before a heatwave arrives
Get ahead while it is still cool. Stock up on bottled or refillable water, and keep some in the fridge so a cold drink is always to hand. Buy any rehydration salts, sun cream and lightweight bedding you might need before the shops sell out. Check that fans work and consider fitting reflective film or blackout blinds to south- and west-facing windows. If anyone in the household relies on medication that must be kept cool, confirm how it should be stored and whether a fridge or cool bag is needed.
Plan your days around the heat too. Move exercise, gardening, dog walks and errands to the early morning or evening, and avoid being outside during the hottest part of the day, roughly 11am to 3pm. Lightweight, loose, light-coloured clothing, a wide-brimmed hat and sunglasses all help, as does a high-factor sun cream reapplied through the day.
Keeping your home cool
The trick with a UK home is to keep the heat out during the day and let it out at night. When it is hotter outside than in, close windows, draw curtains or blinds on the sunny side of the house, and keep internal doors to warm rooms shut. External shading such as awnings or even a sheet over a sunlit window works better than internal blinds because it stops heat before it enters. Turn off lamps, ovens and other appliances that add unwanted warmth.
Once the outside temperature drops in the evening, open windows on opposite sides of the home to create a through-draught and flush the trapped heat out. A fan can help move air, but above about 35C a fan blowing hot air does little to cool the body and may add to dehydration, so rely more on shade, damp cloths and cool drinks. Identify the coolest room, often north-facing or downstairs, and use it for resting and sleeping during the worst of the heat.
Staying hydrated
Drink water regularly throughout the day, before you feel thirsty, because thirst is a late signal that you are already low on fluids. Water is best; limit alcohol, and be aware that very sugary or caffeinated drinks are less effective for rehydration. Pale, plentiful urine is a good sign you are drinking enough, while dark urine suggests you need more. If you have been sweating heavily, oral rehydration salts can help replace lost fluids and electrolytes.
Carrying water with you makes it far easier to keep sipping when you are out or moving between rooms. Eat as normal, since food helps replace salt, and choose water-rich foods such as fruit, salads and cold soups. Anyone on fluid-restricted diets for a medical condition should follow the advice of their doctor rather than simply drinking more.
Recognising heat illness and first aid
Heat exhaustion and heatstroke sit on the same scale but are very different in seriousness. Heat exhaustion brings tiredness, dizziness, headache, feeling sick, heavy sweating, cramps and a fast pulse. It is not usually an emergency if the person cools down within about 30 minutes. Move them somewhere cool, help them lie down and raise their feet slightly, give them water or a rehydration drink, and cool their skin with damp cloths, cold packs under the armpits and neck, or a cool spray.
Heatstroke is a medical emergency. Warning signs include a very high temperature, hot skin that may be dry or still sweating, confusion, slurred speech, seizures, a loss of consciousness, or a person who is not improving after 30 minutes of cooling. Call 999 immediately. While you wait for help, move them to a cool place, remove excess clothing and cool them as quickly as you can with water and fanning. Do not give fluids to someone who is drowsy or unconscious. Treat heatstroke as seriously as any other life-threatening emergency.
Protecting vulnerable people and pets
Heat hits some people much harder than others. Older adults, babies and young children, pregnant women, and people with heart, lung, kidney or mental health conditions or diabetes are all at greater risk, as are those who are bedbound or take certain medicines. Some medications, including diuretics and drugs for blood pressure or mental health, can affect how the body handles heat or how the medicine itself is stored, so ask a pharmacist if you are unsure and never stop prescribed medication without advice. Check on vulnerable friends, relatives and neighbours at least daily during a heatwave.
Pets suffer in the heat too. Provide constant access to shade and fresh water, walk dogs in the cool of early morning or late evening, and never leave any person or animal in a parked car, even for a few minutes and even with a window cracked, as temperatures inside rise to lethal levels astonishingly fast. Watch pets for heavy panting, drooling or collapse and contact a vet urgently if you see signs of overheating.
Power, fridges and related outages
Hot spells can strain the electricity network and cause local power cuts just when fridges and fans are working hardest. If the power goes off, keep the fridge and freezer doors shut to hold the cold as long as possible; an unopened fridge stays safe for a few hours and a full freezer for around a day. Have a torch and a charged power bank ready so you are not caught out, and keep a battery or wind-up radio to follow updates. If refrigerated medicines are affected, contact your pharmacist for guidance rather than guessing whether they are still usable.
What to do when a heat alert is issued
When a Met Office heat-health alert lands, put your plan into action straight away. Close windows and curtains on the sunny side, move to the coolest room, and start drinking water regularly rather than waiting for the heat to peak. Check on anyone vulnerable, plan outdoor jobs for the cool hours, and keep pets shaded and watered. Learn the difference between heat exhaustion and heatstroke so you can act fast, and remember that heatstroke means calling 999 without delay. A calm, prepared response turns a dangerous few days into something you can manage safely.
