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Heat Wave

A heat wave is a prolonged period of high temperatures and humidity. To be classified as a heat wave, this prolonged period must last at least one day. Typically, the prolonged period will last from several days to several weeks. Environment and Climate Change Canada may issue a humidex advisory.

High temperatures and high humidity makes it difficult for the human body to cool itself. Heat can kill by pushing the human body beyond its limit. Under normal conditions, the body’s internal thermostat produces perspiration that evaporates and cools the body. However, in extreme heat and high humidity, evaporation is slowed and the body must work harder to maintain a normal temperature. Heat related illnesses will occur when excessive heat lasts for more than two days.


The parameters for an extreme heat watch, warning or advisory are:

  • Temperatures hover 10 degrees or more above the average high temperature.
  • Lasts for prolonged periods of time.
  • Often accompanied by high humidity that the human body cannot tolerate.

People living in urban areas may be at greater risk from the effects of a heat wave. Stagnant atmospheric conditions trap pollutants in the urban area. Health risks are increased when this unhealthy air is added to the excessively hot temperatures. Asphalt and concrete store heat longer and release this heat gradually at night, which produces significantly higher nighttime temperatures — known as the “urban heat island effect.” The most vulnerable are infants, the elderly, and the sick — especially for those without air conditioning.


During a period of extreme heat students, faculty, and staff should:

  • Slow down and avoid strenuous activity.
  • Avoid too much sunshine.
  • Postpone outdoor games and activities.
  • Stay indoors as much as possible.
  • Keep heat outside and cool air inside.
  • Conserve electricity not needed to keep you cool.
  • Dress appropriately (wear loose-fitting, lightweight clothing, and wear a wide brimmed hat).
  • Drink plenty of fluids even if you do not feel thirsty.
  • Take frequent breaks if you must work outdoors.
  • Avoid drinks with alcohol or caffeine in them.
  • Eat small meals and eat more often.
  • Avoid using salt tablets unless directed to do so by a physician.
  • NEVER leave children or pets alone in vehicles.


Watch for the following signs of heat exhaustion and heat stroke:

Heat Exhaustion

  • Cool, moist, pale or flushed skin.
  • Heavy seating, headache, nausea or vomiting, dizziness, and exhaustion.
  • Body temperature will be near normal.

Heat Stroke

  • Hot, red skin.
  • Changes in consciousness, rapid weak pulse, and rapid shallow breathing.
  • Body temperature can be very high — as high as 40 C (105 F).


If you find someone suffering from a heat related illness take the following actions:

Heat Cramps

Move the person to a cooler place and have them rest in a comfortable position. Lightly stretch the affected muscle and replenish fluids. Give a half glass of cool water every 15 minutes. DO NOT give liquids with alcohol or caffeine in them, as they can make conditions worse. If conditions worsen, call 911. If you are on Campus inform Security Services (204.786.6666).

Heat Exhaustion

Move the person to a cooler place. Remove or loosen tight clothing and apply cool, wet cloths. If the person is conscious, give them cool water to drink (a half glass every 15 minutes). Ensure that the person drinks slowly. DO NOT give liquids that contain alcohol or caffeine. Let the victim rest in a comfortable position and watch for changes in their condition. If conditions worsen, call 911. If you are on campus inform Security Services (204.786.6666).

Heat Stroke

Heat stroke is a life threatening situation. Call 911 immediately. Move the person to a cooler place. Attempt to cool the person using cool wet cloths. Watch for signs of breathing problems. If the victim refuses water or is vomiting or there are changes in the level of consciousness, do not give anything to eat or drink. If you are on campus inform Security Services (204.786.6666).

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