Calgary's mayor is musing about the possibility of making masks mandatory in certain situations and says he could bring forward a draft bylaw to council on July 20.
That would be a step further than the province, which recommends use but hasn't appeared eager to force the issue.
If Calgary did take the step, it would join three other major Canadian cities in making the masks mandatory.
Here are some of the top questions and answers around the move.
What's the current science on wearing masks?
The Public Health Agency of Canada and Alberta Health recommend wearing a homemade or non-medical mask or face covering when it isn't possible to maintain physical distancing, particularly in places like stores and on public transit.
Alberta Health says the use of non-medical masks hasn't been proven to protect the person wearing one, but "it can help protect people from being exposed to your germs."
Both agencies, along with the World Health Organization, say mask use should not replace other preventative measures like physical distancing and proper hygiene.
There is also the risk of self-contamination associated with mask use, if not worn and handled properly.
While Alberta recommends wearing masks under certain conditions, it has resisted mandating the use of masks.
Why is the mayor considering making it mandatory?
Nenshi says mask use indoors in Calgary is too low and is one of three things Calgarians can do to reduce the spread of the virus — along with keeping distance and proper hygiene. He says he's been pushing for increased mask use, but Calgarians aren't taking up the call, so the city might force the issue. He points to the lack of masks on transit as a concern.
What can he do and what would the city have to do to make it mandatory in Calgary?
Nenshi is just one vote on council, so he can't do anything on his own. He has said he could bring a proposed bylaw before council, who would have to vote for moving forward with it.
How would it be enforced?
Bylaw officers and even police could levy fines if they find people without masks in public places, but it would all depend on the specifics of the bylaw.
Calgary bylaw officers tend to prefer education over enforcement.
Would there be exceptions?
The details won't be known before a bylaw is written, but exceptions are likely. In Toronto, which introduced a mandatory mask bylaw, children under the age of two and those with certain health conditions are excluded.
The bylaw there also doesn't apply to some spaces, including schools, child-care facilities, apartment or condo building common areas and restaurant patios.
What other cities have done this?
If Calgary brought in a mandatory mask bylaw, it would be following in the footsteps of other cities across Canada, including Toronto, Ottawa and, soon, Montreal. Quebec is considering a provincewide rule.
What about other countries?
It varies from place to place, but Asian countries have a long history of mask use, and citizens can face steep fines in places like Singapore for not wearing one.
In the United States, multiple states have brought in mandatory mask laws. Vietnam, Slovakia, United Arab Emirates and Germany are just some of the countries that have introduced some form of mandatory mask usage.
What are the different kinds of masks and what protection do they offer?
The masks recommended for public use are non-medical, essentially covering the nose and mouth to avoid droplets from escaping and potentially infecting others. This also includes the free masks handed out by the province.
There are also medical masks.
N95 masks form a seal about the mouth and nose and are designed to filter most viruses. Surgical masks don't form a seal and provide a barrier to splashes and droplets.
Both are used predominantly by health-care workers.
What are common mistakes when wearing a mask?
Don't touch your face and don't touch the front of the mask. Alberta Health recommends adjusting or removing the mask using the ties or ear loops. Even then, wash your hands before putting it on and before taking it off.
The provincial website also recommends you don't share a mask, don't wear a dirty or wet mask, don't wear a torn mask and don't wear the mask under your chin or under your nose as that sort of defeats the point.
If you're wearing a disposable mask, make sure you throw it away. If you're wearing a reusable one, make sure you wash it.
Making these mistakes while wearing a mask can accidentally spread infection rather than prevent it.
Who supports mandatory masks and why?
Some doctors are calling for mandatory masks in Canada, including a group calling itself Masks4Canada. That organization wrote an open letter to the Government of Alberta urging use in all public indoor spaces, in crowds and on transit.
Who doesn't and why?
Others, including Alberta's chief medical officer of health, aren't as convinced. Yet.
Dr. Deena Hinshaw has recommended mask use, and says the province is keeping an eye on the latest research, but she has argued recommendations are working and cautions about the concerns with improper mask use contributing to infection rather than preventing it.
Are you out and about in a mask? CBC Calgary would love to see what you're wearing, especially if it stands out. Send us photos of your masked self to email@example.com, through Facebook or on Twitter.