Extreme Heat

Extreme heat can be dangerous for everyone, but the following groups have higher health risks; people who work outdoors, the elderly, some people with disabilities, people who are pregnant, and children and infants. Knowing how to prepare and keep cool during extreme heat conditions will help you stay safe and healthy.

Heat Alert Criteria

In Southern Ontario, a Heat Warning is issued by Environment and Climate Change Canada when daytime temperatures are expected to be 31ºC or warmer and nighttime minimum temperatures of 20ºC or warmer OR when humidex values of 40 or more are expected.

Heat Warning: Criteria lasts for two (2) days.
Extended Heat Warning: Criteria lasts for three (3) or more days.

Heat Warning and Information System (HWIS)

To help residents of the Haliburton, Kawartha, Pine Ridge District Health Unit (HKPR District Health Unit) area take protective action during extreme heat events, the Ontario HWIS enables public health units to reduce heat-related illnesses by alerting the public about extreme heat events, directing community response and outreach to at-risk and priority populations, and providing individuals with information on how to prevent heat-related illnesses.

There is currently an Extreme Heat Warning for the HKPR District Health Unit area. Visit Environment and Climate Change Canada website for more weather information.

View Heat Warnings

Local Heat Warnings and Alerts

City of Kawartha Lakes No Heat Warning in Effect

County of Haliburton No Heat Warning in Effect

Northumberland County No Heat Warning in Effect

Health Impacts

The symptoms of extreme heat exposure includes heat rash, edema, cramps, and exhaustion. These symptoms can lead to heat stroke (loss of consciousness and death) or can worsen existing chronic conditions such as heart disease, kidney disease, and diabetes. Heat stroke can be identified by the following symptoms:

changes in behaviour (sleepiness or irritable)
dizziness or fainting
rash
nausea or vomiting
headache
rapid breathing and heartbeat
extreme thirst
decreased urination with unusually dark yellow urine

Heat stroke is a medical emergency! If you are caring for someone who has a high body temperature and is unconscious, confused or has stopped sweating, call 911 or proceed to your nearest emergency department immediately.

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.

Sign Up: Extreme Weather Alerts

Receive extreme weather alerts directly to your mobile device.

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Staying Safe During Extreme Heat

Preparing for Extreme Heat

When extreme heat conditions are in the forecast, you can take the following steps to prepare your home.

Install central air conditioning or electric portable/window air conditioning units in your home.
Cover windows that receive morning or afternoon sun with curtains, drapes, blinds or awnings. Consider window coverings that are insulated thermal or blackout to reduce ultraviolet (UV) exposure and reduce heat coming through the window.
Use ceiling fans and/or pedestal fans to circulate air in your home.
Remove heavy bedding, such as comforters, duvets and thick blankets, from beds when sleeping.
Make ice and prepare jugs of cool water.

Staying Cool Indoors

During extreme heat conditions, you should stay indoors to limit sun exposure. To help stay cool indoors, you can:

Take frequent cool showers or baths.
Stay on lower floors if there’s no air conditioning.
Drink water and eat light, regular meals. Be aware that sugary or alcoholic drinks cause dehydration.
Sleep in the coolest room in your home, if possible.

Staying Cool Outdoors

During extreme heat conditions, it may not be possible for some to remain indoors. To help stay cool outdoors, you can:

Spend the hottest part of the day in air-conditioned public buildings (e.g., mall, library, cooling station) or stay in shade covered areas. Many municipalities provide cooling stations during extreme heat. If an “Extreme Heat Alert” is in effect, contact with your municipality to locate what’s available near you.
Drink water every 15 to 20 minutes even if you aren’t thirsty.
Dress in light-coloured, loose-fitting clothing covering as much of your skin as possible.
Wear a wide-brimmed hat to protect your face.
Wear full UVA and UVB protection sunglasses.
Apply sunscreen with SPF 15 or higher 20 minutes before going outside.
Apply lip balm with an SPF 15 or higher.
Monitor yourself and those around you for signs of heat stroke or heat-related illness, and take frequent breaks from the heat.

Who is most at risk?

Everyone's health can be affected by extreme heat and hot weather conditions. However, some people are at a higher risk of experiencing heat-related health impacts, including:

Infants and children
Older adults
People with pre-existing medical conditions and people taking certain medications
People who lack adequate shelter or who are unhoused
Newcomers to Canada
Outdoor workers
Sports/outdoor enthusiasts

Food Safety

The risk of food-borne illnesses increases during the summer because harmful bacteria grow quickly in warm, moist conditions. Here are some outdoor food safety tips to help keep you safe ad healthy during hot temperatures.

Don’t keep food at room temperature for more than one hour on hot summer days.
Don’t leave groceries or food in the car. Consider bringing a cooler with ice to store perishable foods in while you drive. The temperature inside the cooler should be at or below 4°C (40°F).
Marinate and/or thaw frozen meat in the refrigerator or in a cooler filled with ice – not on the counter at room temperature.

Always remember to keep food out of the temperature danger zone of 4°C to 60°C (40°F to 140°F). Harmful bacteria can grow in as little as two hours in this temperature range.

Staying Healthy in the Heat

Learn more about the signs and symptoms of heat illness, who is most at risk and safety tips to help keep you and your family to stay cool.

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Find a Cooling Centre Near you

Contact your municipality for details on local cooling centres.

Algonquin Highlands

Alnwick/Haldimand

Brighton

Kawartha Lakes

Town of Cobourg

Cramahe

Dysart et Al