Transport Canada says if you can’t wear a mask for medical reasons, prove it — or don’t fly | CBC News

Passengers who are unable to wear a face mask due to a medical condition must now present an official doctor’s note stating that they are exempt from the rule, or they will be denied boarding. 
— Read on www.cbc.ca/news/canada/calgary/mask-air-travel-canada-covid-19-1.5681510