Hot weather in Australia is often an excuse to visit your local swimming spot or run through the sprinkler. However, the persistent soaring temperatures of a heatwave can lead to illnesses, such as heatstroke.

In fact, from 2012 to 2022, extreme heat was the biggest cause of weather-related injuries and hospitalisations in Australia.

Here’s what you need to know about this heat-related illness and how to stay safe during a heatwave.

Why is heatstroke a serious condition?

Hot weather can cause heatstroke, a life-threatening condition in which a person can no longer regulate their own body temperature.

If left untreated, heatstroke can lead to complications, such as organ failure, brain damage and death.

Heatstroke is a medical emergency. Call triple zero (000) and ask for an ambulance if someone is experiencing symptoms.

What are the symptoms of heatstroke?

Symptoms of heatstroke include:

• a sudden rise in body temperature (above 40°C)
• red, hot dry skin (because sweating has stopped — though the person may still be sweaty if they have been exercising)
• intense thirst
• rapid pulse and rapid, shallow breathing
• nausea and vomiting
• aggressive or bizarre behaviour, confusion, poor coordination or slurred speech
• loss of consciousness, seizures or coma

Who’s most at risk during a heatwave?

While some people may just become uncomfortable and eat a lot of ice cream, heatwaves can make others seriously ill.

The body usually cools itself down by sweating. When the weather is very hot, your body works even harder to produce sweat. If a person is dehydrated or unable to produce enough sweat, their temperature can rise rapidly.

Certain people are more at risk of this. Elderly people, for example, are less able to produce sweat, while young children produce more body heat, sweat less and have faster rising body temperatures.

These groups are at greater risk of heat-related problems, such as heatstroke:

• people aged over 65 years
• babies and young children
• females who are pregnant or breastfeeding
• people with existing medical conditions, such as heart disease, lung disease, diabetes, kidney disease and mental illness
• people who are overweight or with obesity
• people who are taking certain prescription medicines (talk to your GP about this)
• people who are socially isolated or homeless

If this sounds like you:

• keep your body cool
• keep your home cool — close windows, shut curtains and blinds, use air-conditioning or electric fans
• drink plenty of water
• call a friend or relative if you need help

If you’re not at risk yourself, help others:

• Visit or phone friends, family and neighbours who are more vulnerable.
• Keep children cool and give them plenty of fluids.
• Ensure pets have water and shade.
• Never leave babies, children or animals alone in a car.

How to keep cool during a heatwave

• Drink plenty of water — and check the colour of your wee. If your wee is pale, you’re drinking enough; if it’s dark yellow, you need to drink more.

• Avoid alcohol, tea and coffee because they can make dehydration worse.

• On very hot days, avoid being outdoors between 11am and 5pm.

• At home, you can put wet towels or cool packs on your arms or neck or put your feet in cool water. Take cool showers or baths.

• If you don’t have air-conditioning, visit a cool place like a library, shopping centre or cinema.

• Spend time in the coolest room in your house — this will often be on the ground floor on the south side.

• Use your stove and oven as little as possible.

• If you go outside, make sure to protect yourself from the sun.

• Keep an eye on the weather forecast.

Where to seek help

• If you become very unwell, contact your doctor or go to the nearest hospital emergency department. If you think your symptoms are serious, call triple zero (000) and ask for an ambulance immediately.
• You can call healthdirect on 1800 022 222 to talk to a registered nurse 24 hours a day, 7 days a week (known as NURSE-ON-CALL in Victoria), or use the healthdirect Symptom Checker.
• Read about looking after babies in hot weather.
• Learn about other heat-related illnesses, such as dehydration, heat rash and heat exhaustion.

This post was originally published on 17 December 2019 and has been updated to include the most recent details on this topic.