Extreme weather can put everyone at risk from heat illnesses such as heat stroke, heat exhaustion, heat fainting, heat edema (swelling of hands, feet and ankles), heat rash and heat cramps. Public health encourages everyone to take precautions in the event of extreme heat.
Environment and Climate Change Canada has developed a Heat Warning and Information System for Ontario to give advance warning of heat events. A heat warning is issued in southern Ontario when there will be 2 consecutive days of:
- 31°C or higher during the day AND 20°C or higher at night, OR
- Humidex* values of 40°C or higher (*Humidex describes how hot and humid it feels to the average person.)
Individuals can monitor for heat warnings by downloading the WeatherCAN app or tuning into local radio and TV stations.
Identifying Heat Illnesses
It is important to know how to identify symptoms of heat illness. Symptoms include:
- Dizziness or fainting, nausea or vomiting
- Headache, rapid breathing and heartbeat
- Extreme thirst and decreased urination with unusually dark yellow urine
Preventing Heat Illnesses
Heat illnesses are preventable. Use the following tips from Health Canada to keep you and your family healthy when it is hot and/or humid:
- Stay well hydrated, drink before feeling thirsty (plain water is best)
- Stay in an air-conditioned place
- Avoid sun exposure – stay in the shade, wear SPF 30+ sunscreen, a wide brimmed hat, UVA & UVB protective sunglasses, and loose fitting, light coloured, breathable clothing
- Take cool showers or baths
- Block the sun out by closing awnings, curtains or blinds during the day
- Reschedule strenuous outdoor activities or plan them for cooler times of the day
- Never leave people or pets in a parked vehicle or in direct sunlight
- Visit neighbours, friends and older family members, especially those who are chronically ill, to make sure that they are cool and hydrated
Extreme heat events affect people in different ways, and some people are at a higher risk of experiencing heat-related illness. However, not everyone knows who is at most risk, how to recognize heat-related illness, or what to do in risky situations. The National Collaborating Centre for Environmental Health has created an extreme heat health check tool brochure and an accompanying video to help inform and prepare individuals with all the key information and guidance needed for heat alerts.
Heat-related emergencies
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:
- moving them to a cool place, if you can;
- applying cold water to large areas of the skin or clothing; and
- fanning the person as much as possible.
Cooling and warming centres
Check your municipality’s web page for the most up to date information about cooling centres that may be available.
Resources
- Extreme Heat – Government of Canada
- Infographic: Staying Healthy in the Heat – Government of Canada
