Extreme temperatures

Although climate change is predicted to reduce the frequency and intensity of extreme cold, extreme cold events in the Southeast Public Health region can still occur.

Environment and Climate Change Canada (ECCC) issues cold weather warnings when the temperature or wind chill is expected to reach -35°C for at least two hours.

Visit the Environment and Climate Change Canada weather page for active weather information and alerts.

When your core body temperature drops, or your body is exposed to severe cold, it increases your risk of severe injury and harmful effects such as:

• Frostbite: an injury to the skin that is caused by freezing. The risk of frostbite increases when the wind chill rises. Early signs include pink or reddish areas that may feel numb. As frostbite progresses, the affected area will become white and waxy in appearance.
• Hypothermia: occurs when the body is exposed to cold temperatures, and it begins to lose heat faster than it can be produced. The result is an abnormally low body temperature that can affect brain and muscle function.
• Windburn: occurs when cold wind removes the top layer of oil from the skin causing excessive dryness, redness, soreness, and itchiness.

It is important to watch for signs of frostbite and hypothermia and seek medical attention when necessary. Contact Health811 at 1-866-797-0000 for free medical advice.

While anyone who isn’t dressed warmly is at risk in cold weather conditions, health risks are greatest for: infants and young children, older adults, people living in homes that are poorly insulated (no heat or power), people with chronic medical conditions (e.g., diabetes, peripheral neuropathy, diseases affecting blood vessels, etc.), people who are taking certain medications (e.g., beta-blockers), winter sports enthusiasts, people experiencing homelessness, and people who work outdoors.

Being prepared is key to protecting yourself from negative health impacts due to the cold. Southeast Public Health recommends taking the following actions to prevent cold injuries such as hypothermia and frostbite:

• Wear several layers of clothing and make sure that the outer layer protects you from wind and wetness.
• Cover exposed skin (with hats, mittens, face masks, etc.) to protect against frostbite.
• Drink warm liquids that do not contain caffeine or alcohol, to prevent dehydration.
• Maintain a heated indoor environment above 20°C; hypothermia can even occur indoors when temperatures are 16°C  or lower.
• Avoid strenuous outdoor exercise during cold spells.
• Check in frequently on elderly and vulnerable people; ensure they are in a safe and warm environment.
• Warming centre availability may vary, and some regions may establish temporary locations in response to forecasted weather events. As such, residents are encouraged to contact their local municipality to confirm warming centre locations and hours of operation.

The Government of Canada has more information on how to protect yourself from extreme cold conditions.

Extreme heat events, often called « heat waves » involve high temperatures and sometimes high humidity. Climate change is likely to increase the frequency and intensity of heat waves, representing a growing risk to health.

Environment and Climate Change Canada (ECCC) issues heat warnings when:

• There is a forecast of two or more consecutive days with daytime maximum temperatures of 31°C or warmer, together with nighttime minimum temperatures of 20°C or warmer; or
• When there is a forecast of two or more consecutive days with humidex values expected to reach 40°C or higher.

Visit the Environment and Climate Change Canada weather page for active weather information and alerts.

Conditions during high heat and humidity have the potential to cause dehydration and heat illnesses, which include heat stroke, heat exhaustion, heat fainting, heat edema (swelling of hands, feet, and ankles), heat rash, and heat cramps (muscle cramps). Watch for the following symptoms of heat illness:

• Dizziness or fainting
• Nausea or vomiting
• Headache
• Rapid breathing and heartbeat
• Extreme thirst
• Decreased urination with unusually dark yellow urine

If you experience any of these symptoms during extreme heat, immediately move to a cool place and drink liquids. Water is best. If you are taking medication or have a health condition, ask your doctor or pharmacist if it increases your health risk in the heat and follow their recommendations.

Heat stroke is a medical emergency. Call 911 if you are caring for someone who has a high body temperature and is either unconscious, confused, or has stopped sweating. Contact Health811 at 1-866-797-0000 for free medical advice.

During heat events everyone is at risk; however, health risks are greatest for infants and young children, older adults, people who are pregnant, people who live alone, people with chronic medical conditions (e.g., heart disease, respiratory conditions, diabetes, etc.) or mental illnesses (e.g., schizophrenia, depression, dementia), people who are underhoused or experiencing homelessness, people with limited physical mobility, people who are on certain types of medication (for high blood pressure, for mental illnesses, etc.), people who exercise vigorously outdoors, and people who work outdoors.

If you or a loved one is at an increased risk for heat-related health risks, Southeast Public Health recommends designating someone, a friend or neighbour, to do a wellness check on you or them throughout the duration of a heat event.

Heat illnesses are preventable, and being prepared is key to protecting yourself from negative health impacts due to heat. Southeast Public Health recommends taking the following actions to stay cool:

• Drink plenty of cool liquids, especially water, before feeling thirsty. Find Blue W locations to refill your water bottle with free tap water.
• Avoid direct sun exposure, for example, sit under a tree, wear a wide-brimmed, breathable hat, or use an umbrella.
• Prepare meals that don’t need to be cooked in your oven and block out sun by closing awnings, curtains, or blinds during the day.
• Take breaks from the heat by spending a few hours in a cool place; take cool showers.
• Reschedule strenuous outdoor activity or plan outdoor activities during cooler parts of the day.
• Wear loose-fitting, light-coloured clothing made of breathable fabric.
• Prepare a basement, or cooler part of your home, for occupancy throughout and during the heat event.
• Block the sun out by closing awnings, curtains, or blinds during the day, especially on the westerly side of the home or building.
• Never leave people or pets in your care inside a parked vehicle or in direct sunlight.
• Cooling centre availability may vary, and some regions may establish temporary locations in response to forecasted weather events. As such, residents are encouraged to contact their local municipality to confirm cooling centre locations and hours of operation.

The Canadian Red Cross has more information on how to stay safe during heat waves.