Hyperthermia and heatstroke

young woman suffering heat exhaustion


Heat-induced illnesses such as heatstroke (hyperthermia) and heat exhaustion can be caused by over-exertion, hot and humid weather, inadequate fluid intake, illnesses such as infections, and drugs. If not properly treated these conditions can be fatal.

Note: HYPERthermia is the opposite of HYPOthermia. Hyperthermia is an abnormally high body temperature (overheating) and occurs when your body absorbs or generates more heat than it can release. Hypothermia is when your body is too cold.

Dehydration and heat exhaustion are milder heat-related illnesses.

Heatstroke (hyperthermia)

Heatstroke is a true medical emergency that requires immediate attendance of an ambulance and hospital care. Heatstroke occurs when the body’s temperature reaches and exceeds 40 degrees, and is usually the result of the body being unable to regulate its temperature.

Heatstroke can result in the death of body cells, circulatory collapse and multiple organ failure.

Signs and symptoms of heatstroke

  • Dry, red-hot skin
  • Sweating stops
  • Rapid pulse and fast, shallow breathing
  • Irrational behaviour or confusion
  • Difficulty speaking or slurred speech
  • Problems with movement and coordination
  • Reduction or loss of consciousness
  • Nausea or vomiting
  • Intense thirst

Treatment for heatstroke

The treatment of heatstroke should include:

  • Primary survey (DRSABCD)
  • Call 000 for an ambulance
  • Lay casualty down in the shade or cooler environment (out of the sun)
  • Remove excess clothing
  • Cool the casualty rapidly by applying ice packs to the neck, groin and armpits
  • Sponge or spray the casualty with water and fan their skin
  • Have the casualty sip cool water if conscious
  • Monitor casualty

Do not give the casualty aspirin or paracetamol as this can make things worse.

Heat exhaustion

The body’s response to fluid loss (usually due to excessive sweating), heat exhaustion is relatively easy to manage but must be treated quickly to prevent the more dangerous condition of heatstroke developing.

Signs and symptoms of heat exhaustion

  • Muscle cramps
  • Profuse sweating
  • Headaches or dizziness
  • Thirst
  • Weakness
  • Nausea
  • Dark-coloured urine

Treatment for heat exhaustion

The treatment of heat exhaustion should include:

  • Lying down in the shade or cooler environment (out of the sun)
  • Loosening and removing of excessive clothing
  • Sipping cool water
  • Cooling down with a water atomiser or fan

Read our tips for staying safe in hot weather at the link below.

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