How to Prepare Your Household for Extreme Heat

Extreme heat is a silent hazard. Unlike a flood or a storm, it leaves no broken windows or fallen trees — which is exactly why it is so often underestimated. Yet heat is among the deadliest weather hazards in the world, and deaths climb sharply during prolonged hot spells. Climate change is making heatwaves more frequent, more intense, and longer‑lasting, reaching places and seasons that rarely used to see them.

Heat can affect anyone, but some people are far more vulnerable: older adults, babies and young children, pregnant people, anyone with a heart, lung, kidney or mental‑health condition or diabetes, people taking certain medications, outdoor workers, athletes, and anyone living alone or without a way to keep cool. Humidity makes it worse — when the air is damp, sweat can't evaporate, so the body loses its main way of cooling itself.

The good news is that heat illness is largely preventable. Households that know the warning signs, have a cool space to retreat to, stay hydrated, and check on their most vulnerable members come through a heatwave far better than those caught unprepared. This guide walks through what to do before, during, and after extreme heat.

Understand Your Risk

A heatwave is a prolonged period of excessive heat, often combined with high humidity. What counts as "extreme" depends on where you live — a temperature that's normal in one region can be dangerous in another where homes and bodies aren't adapted to it. Many national services define a heatwave as roughly five or more consecutive days at or above about 27 °C, but harm can begin well below that.

• Humidity multiplies the danger. The "feels‑like" temperature matters more than the number on the thermometer.
• Hot nights are part of the risk. The body needs cooler nights to recover. Several hot nights in a row are when heat illness and deaths rise most.
• Know your local warnings. Sign up for official heat alerts, and keep ReadyEssentials notifications on — the app sends an extreme‑heat alert with safety guidance when one is forecast for your area.

Prepare Before a Heatwave

• Identify your cool space. Find the coolest room in your home (usually shaded, on a lower floor). If your home gets dangerously hot, plan a cooler place to go — a friend's or relative's home, a library, a shopping centre, or an official cooling centre.
• Check your cooling works. Test fans and air conditioning before the hot season, and service air‑conditioning units in advance. Important: a fan stops cooling the body once the air is hotter than about 35 °C and can speed up dehydration — don't rely on a fan alone in extreme heat.
• Keep the heat out. Close blinds, curtains, or external shutters on sun‑facing windows during the day. Consider reflective window film, external shades, or awnings for rooms that overheat.
• Stock up. Keep plenty of drinking water, plus oral rehydration sachets or electrolyte drinks. Choose foods that don't need cooking and won't spoil, and keep a cooler bag ready for food or medication if the power fails.
• Learn the warning signs of heat exhaustion and heatstroke (below) so everyone in the household can spot them early.
• Make a check‑in plan. Agree who will call or visit elderly relatives, neighbours living alone, or anyone at higher risk — at least twice a day during a heatwave.
• Plan for power cuts. Electricity grids are strained in extreme heat and outages are common — see How to Prepare Your Home for a Power Outage.
• Check medications. Some medicines increase heat risk or must be stored cool. Read the labels or ask a pharmacist before a hot spell.

During Extreme Heat

• Drink water regularly — before you feel thirsty. Aim for at least 1.5–2 litres a day, more if you're active or sweating, and avoid alcohol, caffeine, and very sugary drinks.
• Stay in the coolest part of your home. Keep blinds closed during the day; open windows at night only when it's genuinely cooler outside than in.
• Dress for it — light, loose, light‑coloured clothing; a wide‑brimmed hat and sunscreen (SPF 30+) if you must go out.
• Slow down. Postpone strenuous activity, or move it to the early morning or evening. Stay in the shade between 11am and 3pm.
• Cool your body directly: cool (not ice‑cold) showers or baths, damp cloths on the neck and wrists, feet in cool water.
• Never leave anyone in a parked vehicle — child, adult, or pet. The inside of a car can become lethal within minutes, even with a window cracked.
• Check on at‑risk people at least twice a day, in person or by phone.

Recognise and Treat Heat Illness

Heat exhaustion — the warning stage. Signs: heavy sweating; cold, pale, clammy skin; tiredness or weakness; dizziness or headache; nausea; muscle cramps; a fast, weak pulse. → Move the person somewhere cool, loosen tight clothing, cool them with damp cloths and airflow, and give small sips of water. They should improve within about 30 minutes. If they don't improve, or they get worse, treat it as heatstroke.

Heatstroke — a medical emergency. Signs: a very high body temperature; hot, red skin (which may be dry or damp); confusion or slurred speech; a rapid, strong pulse; seizures; loss of consciousness. → Call emergency services immediately. Move the person to a cool place and cool them aggressively — cold water over the body, ice packs to the neck, armpits, and groin. Do not give fluids if they are not fully conscious. → For the step‑by‑step response, see the in‑app first‑aid card Heat Stroke.

After the Heat Passes

• Keep checking on vulnerable people for a day or two — the effects of heat can lag, and some people deteriorate after the peak.
• Rehydrate and rest, and watch for delayed symptoms.
• Restock water and supplies, and note what worked (and what didn't) so you're readier next time.

Keeping Pets Safe

Pets suffer in heat too. Make sure they always have shade and fresh water, walk them only in the cool of early morning or evening, and keep them off hot pavement — if it's too hot for your hand, it's too hot for their paws. Never leave a pet in a parked car. Flat‑faced breeds and older or overweight animals are especially at risk.