British houses are built to keep heat in, which is exactly wrong for a heatwave, and almost none have air conditioning. In a summer with no power, no fans and no fridge, heat illness becomes a genuine household risk rather than something that happens abroad.
The good news is that the dividing line between "manageable at home" and "emergency" is unusually clear.
The thirty minute rule
Heat exhaustion is the body coping badly. Heatstroke is the body's temperature regulation having failed, and it damages the brain, kidneys and other organs within a short time.
Telling them apart
Heat exhaustion:
- Headache, dizziness, feeling faint
- Nausea or vomiting
- Heavy sweating, pale clammy skin
- Cramps in the arms, legs or stomach
- Fast breathing or pulse
- Tiredness and weakness
- Intense thirst
- A temperature of 38°C or above
Heatstroke:
- Confusion, lack of coordination, slurred speech, strange behaviour
- Hot skin that is not sweating, and often looks red or flushed
- Temperature of 40°C or above
- Fast heartbeat, fast or shallow breathing
- Seizures
- Loss of consciousness
- Still unwell after 30 minutes of cooling
Treating heat exhaustion
Straightforward, and it works if started promptly.
- Move them to a cool place. Shade, a north-facing room, a cellar, downstairs.
- Lie them down and raise their legs slightly.
- Remove unnecessary clothing.
- Cool the skin. Cool water on the skin, a wet sheet, a sponge, a fan or anything that moves air. Cold packs wrapped in cloth into the armpits, groin and neck, where large vessels run close to the surface.
- Give plenty to drink. Water, or better, an oral rehydration solution at 6 level teaspoons of sugar and half a teaspoon of salt per litre, since heavy sweating loses salt as well as water.
- Stay with them and watch the clock.
They should feel better within 30 minutes. If they do, keep them cool and resting for the remainder of the day, keep the fluids going, and do not let them go back out into the heat.
Heatstroke
Who is at risk
Heat illness is not evenly distributed, and in a household it will find the vulnerable first.
- Babies and small children. Large surface area, poor temperature regulation, and unable to remove their own clothing or fetch a drink.
- Older people. Reduced thirst sensation, reduced sweating, and often on medication that impairs heat tolerance.
- Anyone with a chronic illness, especially heart, lung or kidney conditions.
- People on diuretics, beta blockers, antihistamines, antidepressants or antipsychotics, all of which can impair heat regulation or fluid balance.
- Anyone working physically in the heat, which in this scenario means whoever is fetching water and wood.
- Anyone in an upstairs room, since heat rises and British bedrooms are frequently the hottest rooms in the house.
Keeping a house cool without power
The preventive half, and the more useful one.
- Close windows and curtains during the day, then open everything at night. This is the opposite of what feels right and it is correct: you are keeping the day's heat out, then flushing the house when the outside air is cooler.
- External shading beats internal. A sheet or blanket hung outside a sunny window stops the heat before it enters the glass. Curtains inside are far less effective.
- Close off unused rooms, and live downstairs. Ground floors and cellars stay markedly cooler.
- Create a through-draught at night by opening windows on opposite sides of the house.
- Damp sheets hung in a doorway or window cool the air passing through them by evaporation, which works well in a dry spell.
- Cook outside, or not at all. A stove indoors in a heatwave is a heat pump pointed the wrong way, and this is where the solar oven and haybox genuinely earn their place.
- Wet skin and moving air is the most effective personal cooling available with no power. A damp cloth on the neck and wrists, and any breeze.
- Sleep downstairs in a heatwave, on the floor if necessary.
- Drink before you are thirsty, and watch urine colour: pale is right, dark means behind.