Heat-Related Illnesses

Preventing Heat-Related Illness:

  • Keep cool - take frequent breaks when working or playing outdoors in extreme heat
  • Wear light-colored clothes and hat - they reflect heat from the sun
  • Avoid strenuous work or sports activities during the warmest times of the day, usually mid-afternoon
  • Drink plenty of fluids throughout the day such as water or sports drinks
  • Do not drink caffeinated drinks or alcoholic beverages

MDH tip sheet on staying cool: Extreme Heat Tip Sheet for Individuals (PDF: 770KB/1 pages). These tips are not a substitute for medical care.

Below are descriptions of some heat-related illnesses. To view data on heat-related illnesses and deaths in Minnesota, see MN Public Health Data Access.



Heat Stroke

Heat stroke is a life-threatening condition. Seek immediate medical attention if you or someone you know is suffering from heat stroke. Heat stroke occurs when the body cannot cool itself. Sweating has usually stopped and the internal (core) temperature of the body becomes too high.

Causes:

Heat stroke is caused by the inability of the body to cool itself after long exposure to extreme heat. Untreated heat exhaustion can lead to heat stroke.

What to look for:

  • Headache
  • Dizziness
  • Nausea/Vomiting
  • Disorientation, agitation, confusion, or loss of consciousness
  • Seizures
  • Hot dry skin
  • Increased body (inner) temperature (above 104 degrees F)
  • Rapid and strong pulse
  • Hallucinations

Treatment:

  • Call 9-1-1 immediately - heat stroke can be deadly
  • Move the person to a cool and shaded place
  • Apply cool water to skin and reapply often
  • Fan the wet skin
  • Apply ice to head, neck, armpits and groin areas
  • The person is unlikely to be able to tolerate drinking or eating.
Go to > top

Heat Exhaustion

Heat exhaustion is a non-life-threatening condition caused by the excessive loss of water and salts from the body due to exposure to extreme heat. Continued exposure may lead to heat stroke, which is life-threatening.

Causes:

  • Long exposure to extreme heat
  • Loss of body water and salts - usually through sweating
  • Not drinking enough fluids
  • Certain illnesses will also cause heat exhaustion

What to look for:

  • Headache
  • Blurred vision
  • Nausea or upset stomach
  • Vomiting
  • Sluggishness or fatigue
  • Thirst
  • Profuse sweating
  • Moderate increase in body temperature

Treatment:

  • Move the person to a cool and dry place
  • Have the person lie down and rest
  • Apply cool water to skin and reapply often
  • Fan the wet skin
  • Have person drink fluids such as water or sports drinks
  • Apply ice to head, neck, armpits and groin areas
  • If the person is showing signs of heat stroke call 9-1-1 immediately
Go to > top

Dehydration

Dehydration is caused by the excessive loss of water and salts from the body due to illness or from prolonged exposure to heat. Severe dehydration can become a life-threatening condition if not treated.

Causes:

  • Extreme heat
  • Severe sweating
  • Diarrhea
  • Vomiting
  • Certain medication can cause the body to lose water, and, if not replenished, can accelerate the onset of dehydration

What to look for:

  • Thirst
  • Dry skin
  • Fatigue
  • Light headedness
  • Confusion
  • Dry mouth (mucous membranes)
  • Increased heart rate and breathing rate
  • Less frequent urination

Treatment:

  • Move the person to a cool and dry place
  • Have the person lie down and rest
  • Have person drink fluids such as water, juice or sports drinks
  • Monitor the person - especially children and the elderly
Go to > top

Back to Hot Weather

Adapted from Ottawa Public Health, City of Ottawa, Ontario, Canada

Updated Wednesday, November 28, 2012 at 04:08PM