For hot weeks, and for anyone with an older neighbour · 11 minutes
Heat is the deadliest weather there is, and almost nobody who dies of it looks like a heatstroke case.
The picture most people have — a collapsed hiker, a marathon runner in the sun — is the rare version. The ordinary version is an eighty-year-old who never left the flat, whose windows stayed shut all night, whose heart and kidneys were already working hard, and who died two days after the hottest afternoon. That is why almost every heat death is preventable with things that cost nothing: shade, air moving at the right hour, water, and one person checking.
Indoorswhere most heat deaths happen, not out in the sun
The nightif it stays hot after dark, the body never recovers
Confusionthe sign that turns heat illness into a 112 emergency
Heat rarely appears on a death certificate. It tips over hearts, kidneys and lungs that were coping, days after the temperature peaked — which is exactly why it is so easy to underestimate while it is happening.
The plan for the day: when to open, when to shut
Most homes are cooled or heated by their occupants without anybody deciding to. The single most common mistake is opening the windows in the afternoon "to get some air", which pumps hot air into a room that had been holding out. Pick the hour and see what to do — and use the rule underneath, which beats any clock.
Tap an hour. Nothing is saved or sent anywhere. The times are a rough guide for a hot summer day in a temperate climate — the temperature rule below is the part that always holds.
midnightnoon23:00
Colour shows how hot indoors typically is at that hour — indoors lags the outdoor peak by several hours.
What actually keeps a room cooler. Shade the glass from the outside if you possibly can — shutters, an awning, a sheet pegged over the window — because once the sun is through the glass the heat is already inside. Close internal blinds and curtains anyway. Keep doors between rooms shut so one cool room stays cool, and turn off everything that makes heat: oven, tumble dryer, computers, and old incandescent lamps.
The fan rule that surprises people. A fan works by evaporating sweat, so it helps as long as the air is cooler than skin. Once the air is around 35 °C or hotter, blowing it over a dry, frail or very old person can add heat rather than remove it — at those temperatures use water on the skin as well as the fan, or move somewhere cooler. A fan is never a substitute for cooling the person down.
The split that decides everything: exhaustion or heat stroke
There are two conditions, and they need opposite amounts of urgency. Getting the difference right is the whole of first aid in the heat.
Heat exhaustion
Heavy sweating, pale and clammy skin
Headache, dizziness, feeling sick, cramps
Tiredness, weakness, fast breathing
Still mentally normal — knows where they are, answers properly
Do: move them somewhere cool, lie them down, raise the feet, remove excess clothing, cool the skin with water, and give them water or an oral rehydration drink to sip. They should feel better within thirty minutes.
Not responding properly, drowsy, fitting, unconscious
Skin that is hot — it may be dry, but it can equally be wet
Not improving after thirty minutes of cooling and drinking
Do: call for an ambulance and start cooling immediately — do not wait, and do not stop when the crew arrives unless they take over.
The one line worth memorising: the moment someone in the heat becomes confused, or stops making sense, or cannot be roused properly, that is no longer exhaustion. It is a medical emergency in which minutes of temperature matter, and cooling comes before transport rather than after it.
How to cool a person, properly
Cooling is a treatment with a dose, and most attempts are far too gentle. The aim is to get heat out of the body fast, in whatever way the situation allows.
Out of the heat, and out of the clothes. Shade, a cooler room, or at minimum out of direct sun. Strip to underwear — clothing is insulation.
Water on the whole skin, and air moving over it. A cool shower, a hose, a bath, wet towels changed often, or wet sheets with a fan. Wetting the skin and fanning it is far more effective than either alone.
Ice or cold packs to the neck, armpits and groin, where big blood vessels run close to the surface. Wrap them in a thin cloth. Cold drinks help too if the person is fully awake and able to swallow.
If someone has collapsed while exercising or working in heat, and a cold bath, pool or tub is available, use it. Whole-body immersion in cold water is the fastest cooling there is, and for exertional heat stroke it is the treatment — keep the head above water and hold them safely.
Keep going until they are clearly better, or the crew take over. Cooling on the way is not a delay to the ambulance; it is the thing the ambulance most wants already started.
Lay them on their side if they vomit or are drowsy, and be ready for shivering — a little shivering is not a reason to stop cooling.
What not to do. No alcohol. No salt tablets unless a clinician advised them. Paracetamol and ibuprofen do not lower a heat-illness temperature and can make things worse — this is not a fever. Do not rub the skin with spirits. Do not put an unconscious person in a bath. And do not give a drowsy or confused person fluids to drink, because they can choke.
Why some bodies cannot shed the heat
The people who die in a heatwave are largely not the people who feel the hottest. Losing heat depends on sweating, on blood being pushed to the skin, and on a heart that can raise its output for days — and all three fade with age or illness.
Over about 65, sweating starts later and produces less, the skin's blood flow responds more slowly, and thirst is genuinely blunted — an older person can be seriously dehydrated without ever feeling thirsty. This is physiology, not stubbornness.
Heart, kidney and lung disease mean the extra work of cooling has nowhere to come from. Most heat deaths are recorded as cardiac or renal.
Dementia or confusion can mean someone dresses for winter, shuts the windows, or forgets to drink — and cannot report feeling unwell.
Infants and small children have a large surface area, little fluid reserve and no ability to move themselves or drink on demand. Never leave a child in a parked car for even a minute: the inside can pass 50 °C in under half an hour, and cracking a window barely changes it.
Pregnancy, obesity, and being unwell with anything at all all reduce heat tolerance, as does a fever from an unrelated infection.
Outdoor and indoor workers — kitchens, warehouses, laundries, building sites, delivery riders — take the biggest exposure, and acclimatising takes one to two weeks of gradual exposure that a hot spell does not allow.
Living alone is the strongest single risk factor of all. Not the temperature, not the flat, not even the illness: the absence of anybody who might notice. That is the one anybody can fix.
The medicines that make heat more dangerous
Several common prescriptions reduce the body's ability to cope, and almost nobody is told this at the pharmacy counter. The answer is never to stop them on a hot day — it is to know that the risk is higher and to be more careful, and to ask for a review before the summer.
Diuretics ("water tablets") increase fluid loss, and the balance between too little and too much fluid is exactly what needs medical advice in a heatwave.
Anticholinergic medicines — including many older antihistamines, some bladder and Parkinson's drugs, and some antidepressants — reduce sweating directly, which removes the main way the body cools.
Antipsychotics interfere with temperature regulation and are strongly associated with heat deaths.
Beta-blockers limit how much the heart can increase its output; ACE inhibitors and ARBs affect thirst and fluid balance.
Lithium becomes dangerous when someone dehydrates, and levels can climb into toxicity in hot weather.
Stimulants, including some ADHD medicines, and recreational stimulants raise heat production and blunt the sense of overheating.
Insulin and some other medicines spoil in heat. Keep them out of parked cars and windowsills, and check the storage advice for anything kept at home.
The useful conversation. Before or early in a hot spell, ask a doctor or pharmacist: do any of my medicines make heat riskier for me, and does my fluid advice change on very hot days? Bring the list. This is a five-minute question with a real answer, and it is far better asked in June than in a hot ward in August.
Heat at work, where the deaths are concentrated
Occupational heat deaths have a pattern that almost nobody expects: they cluster in the first few days of a hot spell or a new job. Acclimatising is real and it takes one to two weeks of gradually increasing exposure — so the fittest new arrival on day one is at higher risk than an unfit colleague who has been out there all summer.
Build up over a week or two rather than starting at full pace, and treat the first day back after a holiday as a first day.
Water, rest, shade, in that order and on a clock — not when you feel like it, because by the time you feel like it you are already behind. Short frequent breaks beat one long one.
Work in pairs and watch each other. Nobody notices their own confusion; a colleague does. Agree that either of you can call a stop without an argument.
Move the heavy work to the early morning and the light work to the afternoon, and change the schedule rather than the effort.
Watch the indoor jobs too: kitchens, laundries, bakeries, warehouses, glasshouses and vans can be hotter than the street, and there is no shade to move into.
Protective clothing changes the maths. Overalls, waterproofs and respirators block evaporation, so the safe limit arrives at a much lower air temperature.
"Toughing it out" is the actual hazard. Heat stroke on a work site usually follows several hours of someone pushing through symptoms they had already noticed.
If a workmate goes confused, aggressive or stops making sense: that is heat stroke, not attitude. Stop everything, get them out of the heat and cooling immediately — soaking their clothes, cold water over the whole body, anything available — while someone calls for an ambulance. Employers' duties differ by country; the physiology does not, and nobody has ever been criticised for stopping work over this.
Drinking, done properly
Drink regularly rather than heavily. Small amounts often keeps up with losses better than a litre at once, and pale straw-coloured urine a few times a day is a decent home check.
If you are sweating for hours, water alone is not enough. Salt matters too: eat normally, salty snacks are fine, or use an oral rehydration solution. Drinking very large volumes of plain water while sweating heavily can dangerously dilute the blood's sodium.
If you have been told to limit fluids — some heart and kidney conditions — do not simply drink more in a heatwave. Ask what your limit should be when it is hot, ideally before it is.
Alcohol is the worst drink in a heatwave: it increases fluid loss, blunts judgement about how hot you are, and disturbs the sleep the body needs to recover.
Cold food counts as fluid. Fruit, salad, yoghurt, cold soup and ice lollies are how you hydrate someone who will not drink — especially an older person or a small child.
Watch the person, not the glass. Dry mouth, headache, dark urine, dizziness on standing, and less urine than usual are the signs that matter more than any counted number of glasses.
The check that prevents the deaths
Every serious analysis of a heatwave lands on the same finding: the people who died were alone, and the people who survived had somebody looking in. It is worth being specific about what "looking in" means.
When you visit
Feel the room. If it is hotter inside than out, open up and get air moving
Look at the windows and blinds — shut and shaded in the day, open at night if it is cooler outside
Check the fridge and the tap: is there cold water, is there food that needs no cooking
Ask what they have drunk today, not whether they are drinking
Notice confusion, unusual sleepiness, or a change in how they are talking
Agree a time you will call tomorrow, and leave your number by the phone
Small things that work
One cool room in the home, prepared in advance, where they sit and sleep
A cheap fan plus a bowl of water and a flannel beats a fan alone
A cool shower or a bowl for feet and forearms, twice a day
Moving the bed to the coolest room for the week
Shopping, prescriptions and any outdoor errands taken over so they need not go out at all
Air-conditioned public places — a library, a shopping centre, a cooling centre — for two hours in the afternoon
Never leave anyone in a parked car. Not a child, not an older adult, not a dog, not for two minutes, not with the windows cracked, not in the shade. And in the heat, do the walk-round: children have died because a routine changed and a sleeping child stayed in the back. Put something you need — a bag, a phone, a shoe — in the back seat so you always look.
The drill: 16 hot days
Sixteen ordinary moments in a heatwave — an afternoon window, a confused neighbour, a football match, a bottle of tablets. Most have an instinctive answer that makes the heat worse. Pick your move; every answer explains why.
The card
Print it before the hot week, and give one to the person you are checking on.