It's Your Health
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Many regions of Canada experience frequent and severe extreme heat events, sometimes called "heat waves" that can put your health at risk. It is important to take precautions to protect yourself and those you may be caring for.
During extreme heat events (as announced by Environment Canada, or your local municipality/Health Unit) conditions of high temperature and/or humidity are present. Your body produces heat, especially during physical activity. Hot air and exposure to direct sun rays or hot surfaces also heat your body. This heat is lost by contact with cool air and by sweat production, which cools your body as it evaporates. Weather conditions play a big role in how your body regulates its temperature. For example, if it's windy, sweat evaporates faster, which helps to cool you. However, high humidity slows down this process, contributing to increased body temperature.
While extreme heat can put everyone at risk from heat illnesses, Heat-Vulnerable Groups:
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 illnesses can lead to long-term health problems and even death. These illnesses include heat stroke, heat exhaustion, heat fainting, heat edema (swelling of hands, feet and ankles), heat rash and heat cramps (muscle cramps) and are mainly caused by over-exposure to extreme heat or over-exertion for a person's age and physical condition.
Heat illnesses are preventable. During very hot weather, the most important thing is to keep cool and hydrated.
Follow these five steps to protect yourself in very hot weather
Tune in regularly to local weather forecasts and alerts so you know when to take extra care.
Arrange for regular visits by family members, neighbours or friends during very hot days in case you need assistance. Visitors can help identify signs of heat illness that could be missed over the phone.
If you have an air conditioner, make sure it works properly before the hot weather starts. Otherwise, find an air-conditioned spot close by where you can cool off for a few hours during very hot days. This will help you better cope with the heat.
Watch for symptoms of heat illness, which include:
If you experience any of these symptoms during hot weather, immediately move to a cool place and drink liquids. Water is best.
Heat stroke is a medical emergency! Call 911 or your local emergency number immediately if you are caring for someone, such as a neighbour, who has a high body temperature and is either unconscious, confused or has stopped sweating.
While waiting for help - cool the person right away by:
Drink plenty of cool liquids, especially water, before you feel thirsty to decrease your risk of dehydration. Thirst is not a good indicator of dehydration.
Dress for the weather - Wear loose-fitting, light-coloured clothing made from breathable fabric.
Keep your home cool
If your home is extremely hot
Never leave people or pets in your care inside a parked vehicle or in direct sunlight.
Reschedule or plan outdoor activities during cooler parts of the day.
Avoid sun exposure. Shade yourself by wearing a wide-brimmed, breathable hat or using an umbrella.
Health Canada is committed to maintaining and improving the health of Canadians. We are working with our partners to better understand the impacts of extreme heat on the health of Canadians, particularly those at greatest risk, and to promote efforts to reduce these risks. We provide information to Canadians on steps they can take to maintain and improve their health, including information on how they can prepare themselves to adapt to prolonged periods of extreme heat.
You can also call toll free at 1-866-225-0709 or TTY at 1-800-267-1245*
Updated: December 2011
Original: October 2006
ęHer Majesty the Queen in Right of Canada, represented by the Minister of Health, 2011
Catalogue # H13-7/21-2011E-PDF
ISBN # 978-1-100-19172-0