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High Temperatures Can Pose a Real Risk to Your Health

Aug 13, 2014
One of the expected impacts of climate change in Simcoe Muskoka is an increase in the intensity and frequency of heat warnings.

One of the expected impacts of climate change in Simcoe Muskoka is an increase in the intensity and frequency of heat warnings. A heat warning is broadly defined as extremely high temperatures potentially combined with high humidity and other environmental factors like poor air quality, which may cause an increase in illness or deaths within at-risk members of the population.

While we thankfully have not had a heat warning this summer, we have come close on a few occasions. Increased temperatures are a public health concern because of the health risk they pose, particularly to our most vulnerable populations. Those considered most vulnerable during heat warnings include: children and infants, seniors, high-intensity athletes, outdoor workers, the homeless and under-housed, pregnant women, people who are overweight or obese, and individuals with mental illnesses which may impact their ability to appropriately cope with the heat.

During heat warnings, the body can become overwhelmed as it is unable to compensate for extreme increases in temperature. High temperatures can impact our health, leading to conditions such as:

  • Heat Rash: A red, bumpy rash.
  • Heat Cramps:  Muscle pain or spasm, normally in the legs, arms or abdomen. Occurs when salt in the body has been depleted.
  • Heat Exhaustion: Signs include heavy sweating, cool and/or moist skin, muscle cramps or pain, headache, nausea, weak pulse, low blood pressure, feeling faint or weak, and chest or abdominal pain.
  • Heat Syncope (Fainting): Due to a lack of appropriate blood flow to the brain, loss of consciousness occurs.
  • Heat Stroke: This is considered a medical emergency. Signs include a high body temperature of 41oC or more, hot and dry skin, rapid pulse, confusion or abnormal mental status, and nausea.
  • Death: While rare, in severe circumstances high temperatures can lead to death.

The health unit is actively communicating Environment Canada’s heat warnings and is supporting and collaborating with local community partners and municipalities to keep communities cool. Understanding how to protect yourself during heat warnings is the first step to preventing heat related illnesses.

  • Avoid sun exposure – shade yourself by wearing a wide-brimmed, breathable hat or use an umbrella
  • Drink cool liquids, especially water, before you feel thirsty to decrease your risk of dehydration
  • Take a break from the heat and spend time in a cool place like basements or air conditioned rooms
  • Frequently check in with neighbours, friends and family members to ensure they are cool and hydrated
  • Wear loose-fitting, light-coloured clothing made of breathable fabric
  • Block sun out by closing awnings, curtains and blinds during the day
  • Never leave people or pets inside a parked vehicle or in direct sunlight
  • Reschedule or plan outdoor activities during cooler parts of the day
  • Take cool showers or baths until you feel refreshed and
  • Choose a sunscreen with SPF 15 or higher that gives protection from both UVA & UVB rays.

To learn more about heat warnings and how increased temperatures can impact your health, call Health Connection at 705-721-7520 or 1-877-721-7520, 8:30 a.m. to 4:30 p.m. Monday to Friday, connecting with us on Facebook or Twitter, or by visiting


Dr. Lee is one of Simcoe Muskoka’s associate medical officers of health.

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