Extreme Heat and Human Health

The health risk from heat exposure are:

• Heat strain (heat exhaustion, fainting, cramps)
• Heat stroke (sweating ceases, headache, dizziness, confusion, nausea, red/hot/dry skin)

Heat stroke is a medical emergency. If you have these symptoms dial 911 immediately.

The best thing to do during an extreme heat event (high 30s degree Celsius/high 90s Fahrenheit) is to keep yourself cool. The best way to maintain your core body temperature in high heat is through evaporation (sweating).

General tips

• Drink plenty of water.
• Be aware that caffeine and alcohol can contribute to or worsen dehydration.
• Avoid physical exertion in the heat. Change your exercise when it's extremely hot (walk in the shade, swim outdoors, play in a sprinkler in the shade).
• If you take medications, check with your doctor or pharmacist about possible side effects during extreme heat.
• Babies, children, pregnant women and the elderly are more vulnerable to extreme heat. Ensure they are adequately protected and kept cool.
• NEVER leave children and/or pets unattended in vehicles.
• Go to a public place that is cool (shopping mall, public library, church, pool). Even a few hours spent in air conditioning can help your body stay cooler when you go back into the heat.
• Think about your neighbours, family and friends that might be isolated or 'shut in'. Check on them, bring water, ensure they are keeping cool.

When you're at home

• Cool your house down. Open windows and chimney flues to let hot air out if the evening air is cool. Avoid the use of ovens, washing machines, and dishwashers that heat up your house during the day.
• Cool yourself off by taking a cool shower, bath or sponge bath.
• Point a fan at a bucket filled with four cups of ice water. This will produce cool air that will help cool you down.
• Electric fans may provide comfort but when the temperature is in the high 30 degrees Celsius (high 90s Fahrenheit), fans will not prevent heat-related illness. Taking a cool shower or bath, or moving to an air-conditioned place is a much better way to cool off.

When you're outside

• Wear loose fitting, light weight, light coloured clothing. Added bonus: you are less attractive to mosquitoes!
• Remember that heat isn't the only thing to be aware of. Avoid damaging UV rays from the sun by applying a sunscreen with sun protection factor (SPF) of 30 or greater, if you work outdoors. Apply insect repellent if you are outdoors at dusk or dawn.
• Wear a wide-brimmed hat and sunglasses (with a UVA/UVB CSA certified seal). If possible, use an umbrella for shade.

It's way too hot! Protect Yourself from Extreme Heat - Health Canada
Keep children cool! Protect Your Child from Extreme Heat - Health Canada
You're active in the heat. You're at risk! Protect Yourself from Extreme Heat - Health Canada

French

C'est vraiment trop chaud! Protégez-vous du temps très chaud - Sante Canada
Gardez les enfants à l'abri de la chaleur! Protégez votre enfant de la chaleur accablante - Sante Canada
Vous êtes actif quand il fait chaud. Vous êtes à risque! Protégez-vous du temps très chaud!- Sante Canada