Heat Waves
Canada is well-known for its very cold winters, but summers can bring high temperatures that can also be dangerous. Excessive heat can cause serious health problems like heat cramps, heat exhaustion, heat stroke, and even death. There are simple steps you can take to stay safe. Learn how to prepare before a heat wave, protect yourself during extreme heat, and recover afterward.
Before a heat wave
- To receive heat warnings on your phone, download the WeatherCAN app, visit Canada.ca/weather or MeteoMedia.com, or listen to local news and weather reports.
- Follow municipal updates about heat advisories and cool spaces
- Check the Air Quality Health Index (AQHI) from Environment and Climate Change Canada. Heat waves often mean poor air quality, so follow the guidance to lower your health risks.
- Share this information with friends, family, or neighbours who may not be tech savvy or may not receive alerts.
- Heat warnings are issued when temperatures stay unusually high for two or more days. Warning thresholds vary by region.
- When the humidex is high, it’s harder for your body to cool down. This is because sweat doesn’t evaporate easily from your skin, making it difficult for your body to release heat.
- Install blinds, heat-resistant curtains, or window film and shade windows from the outside using shutters, awnings, or exterior shades if possible.
- If you don’t have air conditioning, find public spaces where you can cool off, like libraries, malls, splash pads and pools, or community centres, and plan how you will get there.
- Identify the coolest area of your home for resting or sleeping, such as a basement.
- Talk to your household about staying safe in the heat and create a heat plan for your home, workplace, or school. Include how you will handle power outages and where you will go if your home gets too hot.
- Seal drafts with weather stripping or draft blockers. This will help keep cool air inside and hot air outside.
- Review your emergency kit and add heat-specific items such as:
- Extra drinking water (multiple litres per person per day) in case of power outages
- Insulated cooler to keep drinks cool
- Instant ice packs and cooling cloths
- Spray or misting bottles
- Hand fan or battery-operated fan
- Thermometer to monitor indoor temperatures
- Personal thermometer to track body temperature
- Sunscreen, hats, and after-sun lotion
- Extra medications and copies of prescriptions
- Cooling aids recommended by a health-care provider
- Get trained to respond to heat-related emergencies. Find a first aid course near you.
- If you take any medications, check with a pharmacist or healthcare provider to see if they make you more sensitive to heat.
- Discover the signs to recognize and essential steps to take for heat cramps, heat exhaustion, and heat stroke.
- Build and keep good relationships with your neighbours and local groups. This way, you will have a strong support network ready before an emergency happens.
- Find a “heat buddy”. Identify neighbours or community members who might need help during a heat wave, such as seniors, children, or those with medical conditions.
- Cook meals that need the oven ahead of the heat wave.
During a heat wave
- To prevent dehydration, drink cool fluids often – even if you are not thirsty. Tap water is safe to drink in most urban communities in Canada. Avoid alcohol and caffeine because they can make you dehydrated.
- You usually do not need electrolytes to avoid dehydration. Most people can stay hydrated by drinking water and eating a balanced diet. Electrolytes may help treat early signs of dehydration, but they could also be harmful to people with certain health concerns. Please consult your doctor before consumption.
- Spend time in air-conditioned or cool public spaces if your home is too hot.
- Avoid being outdoors during the hottest part of the day (typically between 11 a.m. and 4 p.m.) and seek shade whenever possible. Do outdoor activities during cooler parts of the day. If avoiding peak heat times is not possible, take frequent breaks from physical activity and try to find shade.
- Dress in light, loose-fitting clothing to help air circulate.
- Wear a wide-brimmed hat and apply SPF 30+ sunscreen before going outside. Consider using an umbrella for shade.
- If you do not have air conditioning, keep curtains, blinds, windows, and doors closed during the day to keep hot air outside. If the air quality is safe, open windows at night to let in cooler air. Use ceiling or portable fans to move air.
- Take cool showers or baths. You can also cool down by using a misting bottle or a damp cloth while sitting in front of a fan, or place a bowl of ice in front of a fan.
- Avoid alcohol and caffeine because they can make you dehydrated.
- Choose no-cook or quick-cook meals on hot days, such as salads, fruit, or sandwiches. If you need to cook, do so early in the day and avoid using the oven.
- Pay attention to how you and others feel.
- Check on your neighbours, friends, and others who may need help. Focus especially on those at higher risk, like people who don’t have access to adequate cooling, those who live alone, older adults, babies, outdoor workers and those with chronic illnesses. Checking in-person is best.
- Never leave children alone in a vehicle.
- Ensure pets always have access to fresh water and shade. Consider a cooling mat for pets and never leave them alone in a vehicle.
- Know the signs of heat-related emergencies. If you notice symptoms of heat illness, move to a cool place and drink water. Signs include:
- Hot, dry or sweaty skin
- Severe headache
- Unresponsiveness
- Seizures
- Changed behaviour (bizarre, irritable, aggressive)
- Fast, shallow breathing
- Rapid, irregular, weak pulse
After a heat wave
- If the air quality is safe, open windows and blinds to let fresh air in.
- Check on neighbours, friends, and family, especially those at higher risk.
- Continue drinking plenty of water to stay hydrated.
- Restock any supplies you used, such as water, cooling cloths, or ice packs.
After a Disaster
Recovering after a disaster can be overwhelming. Check out what resources the Red Cross has to offer.
Emergency Preparedness
Take four steps to be prepared for an emergency:
1. Know the risks
2. Make a plan
3. Build a kit
4. Build a network