Extreme Heat/Heat Wave
You can prepare for potential hazards by having a plan in place to deal with the anticipated impacts of an event. Having your plan and emergency kit prepared in advance is the best way to support your family and pets. You may need to Shelter In Place or “hunker down” in your home for at least 72 hours (3 days) without needing to leave for supplies. Plan to be without power in many hazards that could occur.
Many places in Canada have a high number of extreme heat events, often called "heat waves." Extreme heat can put your health at risk, causing illnesses like heat stroke and even death. It is important to take steps to protect yourself and your family.
What are extreme heat events?
- Extreme heat events involve high temperatures and sometimes high humidity. Although the level of temperature extremes may vary between regions, unusually high heat can have negative impacts on your health.
Did you know?
- Over the next 30 years, the number of extremely hot days in a year is expected to more than double in some parts of Canada.
- While extreme heat can put everyone at risk from heat illnesses, health risks are greatest for:
- older adults
- infants and young children
- people with chronic illnesses (like breathing problems, mental illness, and heart problems)
- people who work in the heat
- people who exercise in the heat
- homeless people
- low-income earners
- If you are taking medication or have a health condition, ask your doctor or pharmacist if it increases your health risk in the heat. Some medications can make your skin more sensitive to ultraviolet (UV) rays as well. Talk to your health care provider if you have any questions about your medication.
Stay hydrated
Drink plenty of cool liquids (especially water) before you feel thirsty to decrease your risk of dehydration (not having enough fluids in your body). Thirst is not a good indicator of dehydration. Even if you think you’ve had enough water…you probably haven’t.
- Drink more water - remind yourself by leaving a glass by the sink. Flavouring water with natural fruit juice may make it more appealing. Drink water before, during and after physical activity.
- Eat more fruits and vegetables as they have a high water content.
- Eat small meals and eat more often. If you eat less, you may need to drink more water.
Stay Cool
- Wear loose-fitting, light-coloured clothing and a wide-brimmed hat made of breathable fabric.
- Wear sunglasses that provide protection against both UVA and UVB rays.
- Take a break from the heat. If you must do physical activity in extreme heat, take extra breaks, remove gear to let your body cool off and drink lots of water. Don't expect your usual performance in hot weather.
- Make meals that don't need to be cooked in an oven.
- Block the sun by closing awnings, curtains, or blinds during the day.
- Use a fan to help you stay cool and aim the airflow in your direction.
- Pick up a bag of ice if you don’t have an ice maker. A wrung-out cloth dipped in ice water on the back of your neck will bring relief. You can also freeze a couple of washcloths too.
- If you have an air conditioner, keep it set to the highest setting that is comfortable (somewhere between 22ºC and 26ºC) to reduce energy costs. If you are using a window air conditioner, cool only one room where you can go for heat relief.
- Take cool showers or baths until you feel refreshed.
- Stay inside during the hottest part of the day (10 A.M to 4 P.M.) and limit time in the sun. Avoid strenuous activity and postpone outdoor games and events.
- Spend a few hours in a cool place. It could be a tree-shaded area, swimming facility or an air-conditioned spot like a shopping mall, grocery store, or public library.
- If air conditioning is not available, stay indoors on the lowest floor in a well-ventilated area with fans. Keep shades and blinds closed.
- Never leave children or pets in a hot vehicle.
Avoid exposure to extreme heat when outdoors
- Sunburned skin loses its sweating efficiency. This makes it harder for your body to regulate its temperature.
- Never leave people or pets inside a parked vehicle or in direct sunlight.
- When the outside air temperature is 23ºC, the temperature inside a vehicle can be extremely dangerous - more than 50ºC.
- Reschedule or plan outdoor activities during cooler parts of the day.
- Check the Air Quality Health Index in your area, if available. Air pollution tends to be at higher levels during very hot days.
- Plan strenuous outdoor activities for cooler days or choose a cooler location like a place with air conditioning or with tree shade.
- Avoid sun exposure. Find or bring shade when possible.
- Tree-shaded areas can be as much as 5ºC cooler than the surrounding area.
- Use sunscreen with sun protection factor (SPF) 15 or higher and follow the manufacturer's directions. Don't use sunscreen on a child less than 6 months old.
- Never leave children or pets in a hot vehicle.
Safety tips - What to do if someone gets heat illness:
- Immediately remove the person from the sun.
- If you have any heat illness symptoms during extreme heat, move to a cool place and drink liquids right away. Water is best.
- Heat stroke is a medical emergency! Call 911 or your local emergency number immediately if you are caring for someone who has a high body temperature and is either unconscious, confused or has stopped sweating.
- While waiting for help - cool the person right away:
- Move them to a cool place, if you can.
- Apply cold water to large areas of their skin or clothing.
- Fan the person as much as possible.
See these brochures on heat for specific at-risk groups:
Seniors: It's way too hot! Protect yourself from extreme heat
Parents: Keep children cool! Protect your child from extreme heat
Athletes: You're active in the heat. You're at risk! Protect yourself from extreme heat
Source: Get Prepared and Heat-related illnesses: prevention and treatment
