Heat Stroke – The Darker Side of the Sun

What is Heat Stroke?

Heat stroke is a form of hyperthermia (abnormally raised body temperature) accompanied by changes in nervous system functions. Heat stroke should not be confused with heat cramps or heat exhaustion, less severe forms of hyperthermia.

Heat stroke is defined by a body temperature of at least 104F (40C). It should be treated as a medical emergency and is often fatal if not treated promptly. In normal circumstances the body is able to dissipate heat through the skin or by the evaporation of sweat. However, in extreme heat, high humidity, or during vigorous physical exertion under the sun, the body may not be able to dissipate the heat quickly enough, leading to a rise in body temperature. Heat stroke can also be caused by dehydration. When an individual becomes dehydrated they may not be able to produce enough sweat to dissipate the heat.

Although a heat stroke can affect anyone, some are at a higher risk than others, including: infants, the elderly, athletes and individuals who work outside and exert themselves under the sun. Heat Stroke

Symptoms of Heat Stroke

Heat stroke can vary from case to case, but often an individual will experience the symptoms of heat exhaustion such as nausea and vomiting before progressing to heat stroke. However, in some cases heat stroke can develop rapidly without warning and mimic the symptoms of a heart attack. Common symptoms of heat stroke include:

  • Rapid pulse
  • High body temperature
  • Absence of sweating
  • Difficulty breathing¬†
  • Strange behavior
  • Hallucinations
  • Confusion
  • Agitation
  • Disorientation
  • Seizure
  • Coma


Victims of heat stroke must receive immediate cooling treatment to avoid permanent organ damage. It is important to get the victim to a shady area, remove clothing, apply cool or tepid water to the skin and if available, place ice packs under armpits and groin. If the person is able to drink liquids, have them drink cool water or other cool beverages that do not contain alcohol or caffeine.

Lastly, monitor body temperature with a thermometer and continue cooling efforts until the body temperature drops to 101F (38C). The best prevention measures for heat stroke are to avoid becoming dehydrated and to avoid strenuous physical activity in the hot and humid weather. Wearing hats and light-coloured, lightweight, loose clothes will help keep the body’s temperature balanced. If physical activity cannot be avoided, drinking plenty of fluids such as water and sports drinks will help.

After the prolonged activity in the sun, the body will need a replenishment of electrolytes; sodium is a great source. An electrolyte imbalance can directly lead to one or more of the symptoms above.