For Canadians choosing to fly during the coronavirus pandemic, it has been mandatory to wear a face covering while boarding the aircraft and at all times during the flight, except for eating, drinking, and taking medication. 

Passengers unable to wear a mask due to medical conditions have been exempt from this rule.

On Friday, though, Transport Canada announced that air travellers in Canada will be required to show a doctor's note, proving that wearing a mask is not possible because of medical conditions such as anxiety disorders, lung conditions, and more.

If a passenger cannot provide an official doctor's note, they will be denied boarding. 

WestJet, one of Canada's largest airlines, have since praised their travellers on Twitter for adhering to the rules so far. 

Our guests have been doing an excellent job adhering to the directive, and we thank you for your continued commitment to safety while travelling.

— WestJet (@WestJet) August 10, 2020

"Should a guest be unable to provide a physician's exemption they will be denied travel until clearance is produced," they continued in a separate tweet. 

In their own announcement, the airline said that a medical note must: be issued by a medical professional, be on a official letterhead, be dated, and state the passenger's name and that they have a condition preventing them from wearing a mask. 

Mandatory mask rules have come into effect in cities across the country to help prevent the spread of COVID-19.

In addition, the Canadian and U.S. border remains closed to most non-residents and Transport Canada continues to warn against all non-essential travel. 

International travellers must quarantine for 14 days after returning to Canada.