What To Do If… There’s Extreme Heat

Prepare, Pay Attention, Stay Hydrated

WHAT HAPPENS TO THE BODY DURING EXTREME HEAT?

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

ARE YOU AT RISK FROM EXTREME HEAT?

Everyone is at risk, but some individuals are more susceptible to the effects of extreme heat:

  • 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)

source: Simcoe Muskoka District Health Unit

SAFETY TIPS FROM HEALTH CANADA

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 help. Visitors can help identify signs of heat illness that could be missed over the phone
  • Find ways to keep cool before the hot weather starts. If you have an air conditioner, make sure it works properly. If you have ceiling fans or other fans they can help as long as the humidity isn’t high. Find an air-conditioned spot close by where you can cool off for a few hours on very hot days. This will help you cope with the heat
  • Have cool drinks in your vehicle and keep your gas tank topped up

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

Heat stroke is a medical emergency! Call 911 or your local emergency number immediately if you are caring for someone who has a high body temperature and is either unconscious, confused or has stopped sweating.

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)
  • decreased urination with unusually dark yellow urine
  • changes of behaviour in children (like sleepiness or temper tantrums)

If you have any of these symptoms during extreme heat, move to a cool place and drink liquids right away. Water is best.

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 their skin or clothing
  • fanning the person as much as possible

Call 911 or your local emergency number immediately if you are caring for someone who has a high body temperature and is either unconscious, confused or has stopped sweating.

Watch for symptoms of heat illness

  • dizziness or fainting
  • nausea or vomiting
  • headache
  • rapid breathing and heartbeat
  • extreme thirst (dry mouth or sticky saliva)
  • decreased urination with unusually dark yellow urine
  • changes of behaviour in children (like sleepiness or temper tantrums)

If you have any of these symptoms during extreme heat, move to a cool place and drink liquids right away. Water is best.

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 their skin or clothing
  • 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 (not having enough fluids in your body). 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
  • Drink water before, during and after physical activity

Stay cool
Your body is not used to (not acclimatized to) extreme heat at the beginning of the summer. If you are physically active, you are also not acclimatized if you don’t exercise regularly during hot weather.

Dress for the weather

  • Wear loose-fitting, light-coloured clothing and a wide-brimmed hat made of breathable fabric
  • When you buy sunglasses, make sure they provide protection against both UVA and UVB rays
  • Take a break from the heat

If you must do physical activity in extreme heat, take extra breaks, remove gear to let your body cool off and drink lots of water. Don’t expect your usual performance in hot weather. Give your body time to recover after being in the heat.

Keep your home cool

  • Make meals that don’t need to be cooked in an 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 you have an air conditioner with a thermostat, keep it set to the highest setting that is comfortable (somewhere between 22ºC/72ºF and 26ºC/79ºF). This 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
  • If your home is extremely hot
  • Take cool showers or baths until you feel refreshed
  • Use a fan to help you stay cool and aim the air flow in your direction
  • Spend a few hours in a cool place. It could be a tree-shaded area, swimming facility or an air-conditioned spot like a shopping mall, grocery store, or public library

AVOID EXPOSURE TO EXTREME HEAT WHEN OUTDOORS

Sunburned skin loses its sweating efficiency. This makes it harder for your body to regulate its temperature.

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

When the outside air temperature is 23ºC/73ºF, the temperature inside a vehicle can be extremely dangerous – more than 50ºC/122ºF.
Reschedule or plan outdoor activities during cooler parts of the day.

Before heading out, check the Air Quality Health Index in your area, if available. Air pollution tends to be at higher levels during very hot days.
Plan strenuous outdoor activities for cooler days, or choose a cooler location like a place with air conditioning or with tree shade.
Avoid sun exposure. Find or bring shade when possible.

Tree-shaded areas can be as much as 5ºC/9ºF cooler than the surrounding area.
Shade yourself by wearing a wide-brimmed, breathable hat, or using an umbrella.
Wear loose-fitting, light-coloured clothing made of breathable fabric.
Wear sunglasses that have UVA and UVB protection.
Use a sunscreen with sun protection factor (SPF) 15 or higher and follow the manufacturer’s directions. Don’t use sunscreen on a child less than 6 months old.