Manitoba Health, Seniors and Active Living

Set text to smallest size Set text to normal size Set text to larger size Set text to largest size
Environmental Health

Heat Advisories and Response

Heat and Your Health

Humidity and temperature affect the body’s ability to cope with heat. 

Everyone can be affected by heat. Individuals at increased risk for heat illness include: 

  • people with chronic health conditions,
  • older adults,
  • people living alone,
  • people on certain medications,
  • people performing strenuous activity in the heat,
  • homeless people,
  • infants and young children.

Early in the summer, hot temperatures may have a greater impact on health because people have not had a chance to acclimatize (adapt) to the heat. Heat may have a greater impact on people living in the north because of the acclimatization (adaption) to cooler temperatures.  In addition, there may be fewer ways to get relief from the heat (e.g. fewer buildings with air conditioning).

There can be smaller areas that experience higher temperatures than other parts of a region. For example, downtown Winnipeg is usually hotter than other parts of the city and locations outside of the city.

Be aware of how you are coping with the heat.  Symptoms of heat illness can include:

  • headache,
  • nausea,
  • dizziness,
  • weakness or tiredness,
  • confusion,
  • rapid breathing and
  • rapid pulse. 

If you experience these symptoms or otherwise feel unwell, move to a cool or shaded place immediately, lie down, sip water and sponge your skin with cool water. Emergency medical attention may be required depending on the severity and duration of symptoms.

For more information on heat, visit www.gov.mb.ca/health/publichealth/environmentalhealth/heat.html or contact Health Links–Info Santé at 204-788-8200 or 1-888-315-9257.

^ back to top

Understanding Humidex: Manitoba's Heat Dial

Humidex is a measure of how hot we feel. The Humidex value combines temperature and humidity into one number to reflect the perceived temperature.

The Heat Dial below relates Humidex levels with actions that can be taken to prevent heat illness.

Information on Humidex levels and weather forecasts can be found at www.weather.gc.ca

The Heat Dial

warm hot very hot
Enjoy outdoor activities Over exertion or long periods in the sun may cause heat illness Everyone should consider the impact of heat on their daily activities
  • wear a hat, sunglasses and sun screen
  • drink  water if exercising
  • wear a hat, sunglasses, and  sun screen
  • seek shade 
  • drink water regularly
  • take breaks from the heat during the day
  • limit strenuous activities, especially for individuals at increased risk
  • watch for symptoms of heat illness, especially for individuals at increased risk 
  • wear a hat, sunglasses, and sun screen
  • seek shade 
  • drink water regularly
  • take breaks from the heat during the day
  • limit activities in the heat
  • identify heat illness symptoms early, and get out of the heat and get help if needed
  • check on at risk people

For more information on heat and health effect or prevention measures please see the http://www.gov.mb.ca/health/publichealth/environmentalhealth/heat.html

^ back to top

Heat Advisories

  • Manitoba Health, Seniors and Active Living may issue a heat advisory when most Manitobans should consider modifying their activities to prevent health effects related to the heat.  Advisories are usually issued when the Humidex is 40 or above.
  • Heat related health effects can occur at Humidex levels below 40.  Manitobans are advised to take precautions during hot weather while enjoying outdoor activities.

^ back to top

The Heat Alert Response System (HARS)

  • To lessen the potential health impacts of heat on residents, Manitoba Health, Seniors and Active Living has worked with partners such as the Regional Health Authorities, social services and emergency response sectors to create a Heat Alert Response System (HARS).
  • The HARS is a three- tiered system of alerts (Heat Alerts 1-3) based on the level of heat and the anticipated length of the heat event.  Manitoba Health, Seniors and Active Living notifies partners of the level of extreme heat forecasted so that appropriate preparations and responses can be put into place.
  • The HARS continues to develop with more  partners becoming involved.  The transition from one level of alert to another depends on a number of factors, including the duration of the heat event, the humidity and temperature, and overnight temperatures.   The response system is evaluated each year.  Partner organizations may implement measures to assist people in coping with heat, such as extending public pool hours, handing out water and opening cooling stations.

The graphic below shows the relationship between the HARS and the Heat Dial.

Heat Alert Response System in Relation to the Heat Dial

^ back to top

For more information:
Environmental Health
Public Health
Manitoba Health, Seniors and Active Living

4th Floor - 300 Carlton St.
Winnipeg MB  R3B 3M9
Phone: 204-788-6735
Fax: 204-948-2040