Ontarians reminded to take measures to stay cool amid high temperatures

ONTARIO’S Interim Chief Medical Officer of Health is reminding all Ontarians to protect themselves and their families from extreme heat this summer.

Dr. David Williams is asking people to take simple measures to avoid heat-related illness as temperatures in parts of the province soar. Moving to a cool place and drinking plenty of cool liquids–especially water–is the best way to protect your health during extreme heat. Other protective measures Ontarians can take include:

  • Wearing loose-fitting, light-coloured clothing and wide-brimmed hats made of breathable fabric
  • Planning outdoor activities during cooler parts of the day or choosing indoor locations with air conditioning or outdoor locations with shade (tree-shaded areas can be as much as five degrees Celsius cooler than a surrounding, non-shaded area)
  • Taking extra breaks if you must do physical activity in extreme heat, removing gear to let your body cool off and drinking lots of water
  • Taking cool baths or showers
  • Keeping your home cool by turning off indoor lights; closing awnings, curtains or blinds to block out the sun; and using an air conditioner at the highest, comfortable setting (between 22 and 26 degrees Celsius) or if using a window unit, cooling one room where you can go for relief from the heat.

Dr. Williams is also asking people to check on friends, family and neighbours regularly who may be at high risk during extreme heat. Those most vulnerable include infants and young children, older adults and people with chronic medical conditions like heart disease or diabetes.

If you have concerns about any symptoms, contact your health care provider right away. Check with your local public health unit for updates on local air quality, the location of the nearest cooling centre, public pool and other information.



  • Never leave people or pets inside parked vehicles as temperatures inside can become extremely dangerous during hot days and reach over 50 degrees Celsius.
  • Symptoms of heat illness can include dizziness, nausea and headache. If you, a family member or someone you know are experiencing symptoms of heat illness, immediately move to a cool place and drink liquids. Water is best.
  • Extreme heat can also cause adverse health effects including heat cramps (usually in the legs or abdomen), heat edema (swelling of the hands, feet and ankles), heat exhaustion (characterized by heavy sweating, dizziness, nausea, vomiting and fainting) and heat stroke. Heat stroke is a medical emergency with symptoms including dizziness, confusion and an altered mental state.
  • 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.