Hot weather and extreme heat are common in Simcoe Muskoka and are increasing with climate change. Heat can make people very sick and can lead to serious, sometimes life-threatening health problems. Indoor temperatures of 31 C or higher can be dangerous. You can protect yourself and those around you by taking simple steps to stay cool, watching for signs of heat illness and checking on others during hot weather.

Heat warnings and what they mean

Extreme heat warnings are issued by Environment and Climate Change Canada in Simcoe County and the District of Muskoka when daytime temperatures are expected to reach at least 31 C and overnight temperatures are least 20 C, or when the humidex reaches at least 40 C for a minimum of two days.

How to stay safe

Take these steps to stay safe in extreme heat: 

• Get to a cool place. Use air conditioning if you can. You can also go to a library, community centre, mall, shaded area or other cool space.
• Drink water often even if you do not feel thirsty. Avoid alcohol and too much caffeine.
• Slow down. Avoid hard activity and plan outdoor tasks for cooler times of the day.
• Keep your home cool. Close blinds or curtains during the day. Open windows at night if it is cooler outside. Use air conditioning if you have it.
• Do not rely on a fan as your main way to cool down during extreme heat. Use fans only to move cooler air indoors in the evening or early morning.
• Wear light, loose clothing. Wear a hat and sunglasses when outside.
• Check on family, friends and neighbours. Check more often on people at greater risk.
• If you live alone or need extra help, ask someone to check on you during hot weather.

Cooling Spaces

Cooling spaces are available throughout Simcoe Muskoka to provide relief from the heat. They are usually found in municipal buildings, libraries, and community centres and open to the public during regular business hours.

To find an open cooling centre near you, visit the County of Simcoe and District of Muskoka's websites.

Signs of heat illness and when to get help

Heat can make you sick quickly. It can cause dehydration, heat cramps, heat rash, heat exhaustion and heat stroke. It can also make health conditions like lung and heart problems worse. Heat can affect metal health and may increase mood or behaviour changes.

Pay attention to how you and those in your care feel during hot weather. Take action right away if the following signs of heat illness appear.

Mild to moderate symptoms

• Headache, nausea or irritability
• Weakness, tiredness, feeling unwell, light-headedness or diziness
• Disorientation or confusion
• Extreme thirst, peeing less than usual or dark yellow pee
• Skin rash, muscle camps or very warm, sweaty skin
• Increased heart rate or body temperature about 38 C

Remember: Mild to moderate heat illness can quickly become severe. Move to a cool place, drink water and cool your body.

If symptoms get worse or you are unsure what to do, contact a health-care provider or call 811 or visit Health811.

Severe symptoms

• Severe nausea or vomiting
• Fainting, loss of consciousness or hard to wake up
• Confusion, disorientation, trouble speaking or movement problems
• Not sweating, hot flushed skin or pale skin
• Not urinating or only very small amounts
• Fast breathing or fast heartbeat
• Body temperature over 39 C

Call 911 right away if someone has severe symptoms. Severe heat illness and heat stroke are medical emergencies. While waiting for help, cool the person by:

• Moving them to a cool place
• Removing extra clothing
• Putting cold water on their skin

Who is at greater risk?

Heat can affect everyone, but some people are at greater risk of heat-related illness. Factors like weather, housing conditions, age, overall health, activities and access to resources all play a role. Those who may be more at risk include:

• Older adults
• Infants and young children
• People with chronic health conditions, such as breathing problems, mental illness or heart problems
• People experiencing homelessness
• People who work or exercise in the the heat
• People who are unable to keep their living space cool
• People who live alone or need extra help during a heat event

Heat warnings and what they mean

Extreme heat warnings are issued by Environment and Climate Change Canada in Simcoe County and the District of Muskoka when daytime temperatures are expected to reach at least 31 C and overnight temperatures are at least 20 C, or when the humidex reaches at least 40 C for a minimum of two days.

Heat, power outages and air quality

Heat events can overlap with power outages and weather events that can affect your health so it's important to be prepared.

Power outages

During a heat event, storms or a high demand for electricity can result in a power outage. This may affect your access to air conditioning or fans. The following steps can help to prepare and cope with a power outage during a heat event.

• Take steps to keep cool air in and hot air out by covering windows with blinds or curtains, outdoor shutters, awnings, and weather-strip doors and windows.
• Have an emergency kit available that includes food, water, and a battery-operated radio and flashlight.
• Go to a cooler space or an outside shaded area near water, if possible, if your home becomes too hot. Remember that indoor temperatures of 26 C increase the risk of heat illness and temperatures of 31 C or higher are dangerous.

Poor air quality

Hot and humid weather can lower air quality and increase the risk of wildfires. During these types of events:

• Check the Air Quality Index to help you make decisions about your health. If indoor temperatures are comfortable, keep windows and doors closed.
• For most people, exposure to heat is a bigger risk to health than exposure to wildfire smoke. If you cannot get cool inside, seek cooler spaces in your community or go outside, even if there is wildfire smoke. This is safer than staying in indoor environments that are too hot.

Additional resources

For more information on extreme heat and related resources visit Health Canada's website.