Complications of heat-related illness

Complications of heat-related illness

Complications of heat-related illness

When to see a doctor

Heatstroke (also known as sun stroke) is the most severe phase of hyperthermia and is considered a medical emergency. The body is incapable of cooling itself (failure of internal regulation of temperature). Once internal body temperature is in excess of 40°C (104°F) and rising rapidly, a person is considered to have reached the stage of heatstroke. At this temperature, the brain and other crucial internal organs are at risk of serious damage or total failure, which can result in permanent disability or even death. The severity of the damage depends on the length of time a person has been exposed to intense heat.

Heatstroke is classified as either exertional heatstroke (EHS) or non-exertional heatstroke (NEHS). Exertional heatstroke refers to relatively young individuals that are otherwise healthy, after having engaged in strenuous activity in intense heat conditions (hot weather). Classic heatstroke is also known as NEHS and refers to very young, elderly or chronically ill individuals who develop the condition without having engaged in strenuous activity.

Warning signs of heatstroke can include:

  • High internal body temperature
  • A rapid heart rate (or pulse rate which can be weak) – sometimes a pulse rate can be slow and weak as well
  • Skin changes – red and hot, and moist or dry (profuse sweating may have ceased at this stage)
  • Headache
  • Breathing difficulties (rapid, shallow breathing)
  • Loss of coordination
  • Dizziness or feeling woozy and faint
  • Restlessness
  • Confusion and mood changes such as grouchiness and irritability or other strange behaviour (sometimes the sufferer may become delirious or experience hallucinations)
  • Staggering
  • Nausea and vomiting
  • Seizures
  • Loss of consciousness (or falling into a comatose state)
  • Pupil dilation
  • Muscle rigidity

What to do when heatstroke reaches a heat emergency stage

Heatstroke is considered a heat emergency or health crisis. Generally, once heat cramps, rash, oedema, syncope, heat exhaustion occur, it is best to consider medical intervention as the severity of a person’s condition can escalate quickly to heatstroke and become life-threatening.

Heat emergencies are more common in those with a particular difficulty in regulating body temperature, such as those who are overweight, older in age or very young, or anyone who has been consuming alcohol.

If able, a person should:

  • Try and move to a cooler location (i.e. an air-conditioned room or run a cool – not ice cold - bath or shower)
  • Drink fluids such as water and electrolyte-filled drinks (such as sports drinks) to rehydrate the body
  • Place cool compresses or ice bags under the armpits or around the groin area to encourage rapid cooling

If self-administered cooling and rehydration treatments before heatstroke stage do not appear to show improvement in a short space of time, it may be increasingly difficult for a person to prevent the heatstroke stage on their own. Once symptoms of vomiting, seizures or loss of consciousness develop, it is best to seek emergency medical treatment. Recognising all the signs early enough can help to prevent a heat emergency.

With proper treatment by a medical professional, most can recover from a heat emergency within a matter of days. The sooner treatment is administered, the less chance of severe damage (often as a result of swelling and inflammation) being caused to the brain and vital organs. Damage experienced may be permanent (or life-long) if not seen to by medical professionals quickly enough.

PREVIOUS What are the phases and signs of hyperthermia?
NEXT What are the risk factors for hyperthermia?