Extreme Heat

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Climate change is likely to have wide-ranging effects on human health in coming years – it is expected that heat waves will occur more frequently, be hotter, last longer and have higher levels of humidity. Warmer temperatures and prolonged heat waves will also bring an increase in air pollution (Health Canada).

What happens to the body during extreme heat?

The body’s temperature control system can become overwhelmed. Sweating helps to cool the body, however, when the humidity is high, sweat will not evaporate as quickly, preventing the body from releasing heat quickly. Very high temperatures can damage the brain or other vital organs.

Everyone is at risk, but some individuals are more vulnerable (Health Canada):

• infants and children

• seniors

• the homeless

• pregnant women

• individuals who are ill or on certain medications

• individuals who exercise vigorously or play sports outdoors

• individuals who do strenuous outdoor work for prolonged periods of times (e.g. construction or manual labour)

• individuals who are overweight (tend to retain more body heat)

Children have a high metabolic rate and therefore produce more heat. Also, their capacity to sweat is not as great, so it is more difficult for them to release heat. The effects of dehydration are greater in children.

Yes, children with diabetes, anorexia, obesity, developmental delays, cystic fibrosis, heart disease and diarrhea are at an even greater risk.

What should be done to protect children’s health when temperatures and humidity are high?

Keep the children cool and use common sense:

• be sure children drink plenty of fluids (non-caffeinated)—even more than their thirst indicates

• wear lightweight, light-colored, loose-fitting clothing

• stay cool indoors and if possible, stay in an air-conditioned place

• electric fans provide comfort by increasing evaporation, however when the conditions are extreme, fans will not prevent heat-related illness

• keep physical activity to an absolute minimum

• draw blinds/curtains to prevent radiant heat from entering classrooms

• never leave babies or children unattended in a car

Why are seniors at risk?

• Elderly people do not adjust to sudden changes in temperature.
• They are more likely to have chronic medical conditions that can upset the normal response to heat.
• They are more likely to take medications that impair the body’s ability to regulate its temperature or that inhibit sweating.

What should seniors do to protect themselves?

• Drink plenty of fluids (consult with your doctor to see how much fluid to drink).

• Rest indoors and if possible, stay in an air conditioned place.

• Wear lightweight & loose-fitting clothing.

• Keep physical activity to a minimum.

• Use a fan and draw blinds/curtains to prevent radiant heat from entering.

What you can do to help protect elderly relatives or neighbours?

• Visit or check in with them regularly.
• Take them to air conditioned locations if they have transportation problems.
• Ensure they have an electric fan.

Minimizing Your Risk – General Precautions

Keep out of the heat

• Be aware of environmental conditions such as the smog status, air/UV/humidity index.
• Try to limit your activity to the morning and evening. 
• Rest often in a shady area.
• Wear a wide-brimmed hat, sunglasses and light/loose-fitting clothing.
• Drink plenty of water.

Stay Cool

• Stay indoors. Spend time in an air-conditioned building
• Draw blinds/curtains to prevent radiant heat from entering.
• Take cool showers or baths.

Drink Fluids Regularly

• Drink plenty of water or natural fruit juices. Do not wait until you are thirsty.
• Avoid alcohol, caffeine, or beverages with large amount of sugar.
• Heavy sweating causes the body to lose salts and minerals.
• If you have a health condition, check with your doctor before increasing fluids.

How will I know how to treat a condition caused by extreme heat?

Below you will find a table to assist you in recognizing conditions caused by extreme heat, symptoms to look for and how you can prevent these conditions from occurring.

Where can you go for more information?

For more information call Your Health Connection at 721-7520 (1-877-721-7520) or visit the following websites:

Health Canada

Centre for Disease Control and Prevention