TORONTO -- Starting Thursday, temperature screening is beginning in phases at Canada’s 15 busiest airports, including Toronto’s Pearson Airport, in response to COVID-19.

The rule also kicks in today at three other international airports in Vancouver, Calgary and Montreal.

On or before September 30, mandatory temperature screening will begin at Canada’s next 11 busiest airports in St. John’s, Halifax, Quebec City, Ottawa, Toronto-Billy Bishop, Winnipeg, Regina, Saskatoon, Edmonton, Kelowna and Victoria.

The Canadian Air Transport Security Authority (CATSA) says all passengers departing from these airports will be required to undergo temperature screening before proceeding to the screening checkpoint.

Travellers will have their temperature taken either by a temperature scanning camera on a stand or by a contactless, hand-held thermometer.

CATSA says glasses must be removed before a temperature reading can be taken by the camera and people wearing headwear may have to temporarily adjust it to have their temperature read. Private screening areas are available for those who want to make adjustments in private.

Passengers with temperatures below 38C will be able to proceed to the checkpoint.

Those with temperatures at or above 38C on the first screening will be asked to wait 10 minutes in a nearby designated waiting area, unless they show a medical certificate stating that their elevated temperature is not due to COVID-19.

If a second reading shows a temperature above the threshold or if the passenger refuses a second reading they will not be allowed to continue their journey.

Travellers will not be allowed to get a third temperature check.

Transport Canada says passengers with an elevated reading will not be permitted to enter a restricted area at any airport in Canada for a period of 14 days after their temperature screening.

Masks or face coverings are also mandatory at Canadian airports. Exemptions are for passengers with health or medical reasons and children under the age of two.