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Environmental and Workplace Health

It's way too hot! Protect Yourself from Extreme Heat

ISBN: 978-1-100-17641-3
Cat. No.: H128-1/10-631E
HC Pub.: 110005

Know your risks

Hot temperatures can be dangerous, especially if you have:

  • breathing difficulties;
  • heart problems;
  • hypertension;
  • kidney problems;
  • a mental illness such as depression or dementia;
  • Parkinson's disease; or
  • if you take medication for any of these conditions.

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 Illness

Heat illnesses include heat stroke, heat exhaustion, heat fainting, heat edema (swelling of hands, feet and ankles), heat rash and heat cramps (muscle cramps). Heat illnesses can affect you quickly and are mainly caused by over-exposure to heat or over-exertion in the heat.

Prepare for the heat

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 cope with the heat better.

Pay close attention to how you - and those around you - feel

Watch for symptoms of heat illness, which include:

  • dizziness or fainting;
  • nausea or vomiting;
  • headache;
  • rapid breathing and heartbeat;
  • extreme thirst (dry mouth or sticky saliva); and
  • decreased urination with unusually dark yellow urine.

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 a 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.

Stay hydrated

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.

  • Remind yourself to drink water by leaving a glass by the sink.
  • Flavouring water with natural fruit juice may make it more appealing.
  • Eat more fruits and vegetables as they have a high water content.
  • If you eat less, you may need to drink more water.

Stay cool

Dress for the weather - Wear loose-fitting, light-coloured clothing made from breathable fabric.

Keep your home cool

  • If you have an air conditioner with a thermostat, keep it set to the highest setting that is comfortable (somewhere between 22°C/72°F and 26°C/79°F), which will reduce your energy costs and provide you with needed relief. If you are using a window air conditioner, cool only one room where you can go for heat relief.
  • Prepare meals that don't need to be cooked in your oven.
  • Block the sun by closing awnings, curtains or blinds during the day.
  • If safe, open your windows at night to let cooler air into your home.

If your home is extremely hot:

  • Take a break from the heat by spending a few hours in a cool place. It could be a tree-shaded area, swimming facility or an air-conditioned spot such as a shopping mall, grocery store, place of worship or public library.
  • Take cool showers or baths until you feel refreshed. Make sure to use non-slip surfaces in the tub and shower, and wipe up moisture immediately to avoid slipping.
  • Use a fan to help you stay cool and aim the air flow in your direction.

Avoid exposure to very hot temperatures when outdoors

Never leave people or pets in your care inside a parked vehicle or in direct sunlight.

  • When outside air temperature is 23°C/73°F, the temperature inside a vehicle can be extremely dangerous - more than 50°C/122°F.

Reschedule or find alternatives

Reschedule or plan outdoor activities during cooler parts of the day.

  • Before heading out, check the Air Quality Health Index (AQHI) in your area, if available - air pollution tends to be at higher levels during very hot days.
  • If you are in an area where mosquitoes are active, protect yourself with insect repellent and follow the manufacturer's directions.

Avoid sun exposure

Shade yourself by wearing a wide-brimmed, breathable hat or using an umbrella.

  • Tree-shaded areas could be as much as 5°C/9°F cooler than the surrounding area.
  • Use a sunscreen that is SPF 15 or higher and follow the manufacturer's directions. Remember, sunscreen will protect against the sun's ultraviolet (UV) rays but not from the heat.
    • Sunscreen and insect repellents can be safely used together. Apply the sunscreen first, then the insect repellent.

Additional Resources

  • Public Health Agency of Canada's "You CAN prevent falls!" www.phac-aspc.gc.ca/seniors-aines/publications/public/injury-blessure/prevent-eviter/index-eng.php
  • Health Canada's "It's Your Health - Insect Repellents" www.hc-sc.gc.ca/hl-vs/iyh-vsv/life-vie/insect-eng.php
  • Health Canada's "Sun Safety" www.hc-sc.gc.ca/hl-vs/pubs/sun-sol/safety-prudence-eng.php
  • Health Canada and Environment Canada's "Air Quality Health Index" www.airhealth.ca