Many American cities now require citizens to wear face masks in public at all times, but Canada has become the first country to require them on airlines.
As of Monday, all passengers on flights within, to, or from Canada must wear some type of covering for the nose and mouth. No covering, no flight.
Passengers will be checked for masks at airport security checkpoints.
For travel on Canada's trains, boats, and buses, the requirement is less stringent. There, masks are "encouraged . . . as much as possible," but so far, not possessing one will not necessarily result in ejection.
Air Canada has been recommending face masks since early April, but this is the first time masks have been mandated across all airlines in Canada. Canadian authorities have not announced an end date for the new measure.
And no, using the drop-down emergency oxygen mask on the plane won't count.