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Public health & wellbeing > Disaster management

Heat-related illness

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During extremely hot weather, it is easy to become dehydrated or overheat. If this happens you may develop a heat-related illness such as heat cramps, heat exhaustion or even heat stroke. If you suffer from a chronic health condition, it may become worse during hot weather. So it is important for you to plan ahead to stay healthy in hot weather.

What happens to your body in extreme heat?

When the weather is very hot, your body has to work harder and produce more sweat to keep cool.

Under some conditions, sweating just isn't enough and your body temperature can rise rapidly. This is more likely to happen when it is humid, or when you are dehydrated and can't produce enough sweat. It's important that your body temperature stays between 36.1 - 37.8°C. If your temperature rises above this, you may develop signs of heat related illness.

Who is at risk?

All Queenslanders are at risk during periods of hot or prolonged high temperatures; however some people are at a higher risk of harm, such as:

The best way to reduce the risk of heat-related illness is to drink plenty of water and keep your body as cool as possible.

Common symptoms of heat-related illnesses

This chart lists the most common symptoms of heat-related illness that can affect people. Please note that the presence of symptoms may vary from person to person.

Heat-related illness Symptoms First aid
  • drink plenty of water or alternate with diluted fruit juice (1 part juice in 4 parts water); avoid alcohol and drinks high in caffeine and sugar
  • move to a cool place, lie down and remove excess clothing
  • seek medical help if start to feel unwell
Heat cramps  
  • profuse sweating
  • painful muscle cramps usually in legs and abdominal muscles
  • stop activity and sit quietly in a cool place
  • increase fluid intake
  • rest a few hours before returning to activity
  • stretch and gently massage affected muscles
  • seek medical help if cramps persist
Heat exhaustion  
  • pale complexion and profuse sweating
  • fatigue, weakness and restlessness
  • headache, dizziness
  • nausea, vomiting
  • weak rapid heart rate
  • breathing fast and shallow
  • muscle cramps, weakness
  • fainting
  • move to a cool place, lie down and remove excess clothing
  • to cool down the body try:
       -  cool shower, bath or sponge bath
       -  place moist, cool cloths on forehead, wrists, sides of neck, underarms and groin area, fan continuously
  • give small sips of cool water or diluted fruit juice or cordial (1 part juice in 4 parts water)
  • if recovery is not prompt or vomiting occurs, seek emergency medical assistance
Heat stroke  

More severe and dangerous form of heat related illness.

  • confusion, poor coordination or slurred speech
  • hot, dry skin possibly not sweating
  • fast and shallow breaths
  • rapid pulse
  • extreme fatigue, headache, fainting
  • vomiting and diarrhoea
  • loss of consciousness

This is a medical emergency - call triple zero (000), then:

  • check person’s airway, breathing and pulse - if unconscious position on their side and commence CPR if required
  • seek urgent medical advice if ambulance delayed
  • if possible, move person to a cool place, lie them down and remove excess clothing. Most important treatment is to cool the person rapidly
  • to cool the body place moist, cool cloths on forehead, wrists, sides of neck, underarms and groin area, fan continuously
  • give small sips of fluids if conscious and able to swallow
  • do not give any medications unless they are prescribed by the doctor

Where to get help

For more information or support during heat event or a heatwave:

In an emergency, call triple 000.

 The following information may assist you:

Queensland Health would like to acknowledge that this information is based on the work undertaken by NSW Health—Environmental Health Services.

Last Updated: 23 November 2015
Last Reviewed: 23 November 2015

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