TORONTO -- Some Canadians concerned about coronavirus in the wake of one confirmed and another presumptive case in Canada have been strapping on surgical masks to go outside. But can these face masks actually guard against the virus?

According to doctors, the answer for the average person is largely no -- but context and setting need to be taken into account.

WHEN SHOULD YOU WEAR A MASK?

“I think the important part here is trying to use them in the right context,” Dr. Susy Hota told CTV News on Friday.

Surgical masks are a common -- and necessary -- sight in a hospital setting, she said, where patients, family members, doctors and nurses are in a closed environment with numerous individuals impacted by various illnesses.

But that’s very different from wearing a surgical mask while walking down the street.

“At this time there’s absolutely no reason for people to be walking around wearing masks in public,” Hota said, adding that the only reason to do so would be on the advice of a health-care professional for a reason unrelated to coronavirus.

In a press conference Monday updating the public on the new presumptive case of coronavirus in Ontario, Chief Medical Officer of Health Dr. David Williams said his office has “never recommended the wearing of masks in public.”

IS ONE TYPE OF MASK MORE USEFUL THAN ANOTHER?

Surgical face masks have been flying off the shelves in several cities around Canada ever since coronavirus reports started ramping up.

The most common face masks are loose surgical masks with elastic loops that go around the ears. The masks cover the mouth without creating a seal around it. One side is generally coloured blue, and is meant to face outwards. The top of the mask has a metal strip to mold to the bridge of the nose.

These masks do little for a healthy person, doctors say, but they could be useful for someone who is sick and trying not to spread the illness.

"If you're someone who's actually sick, you might have a cold or flu and you want to protect others, that type of mask will protect droplets from going out into the air (when you cough or sneeze),” Gianni Del Negro, a pharmacy manager with London Drugs in Vancouver, told CTV Vancouver.

These surgical masks will not protect you from the new coronavirus, he said.

The N95 respirator mask, which is made of a thicker material and designed to fit more closely to the face, may be more effective at blocking viruses in general, he added, but it needs to be fit tested, worn properly and replaced frequently -- making them inefficient for regular use by the public.

However, there’s no evidence that those masks would work against the new coronavirus either.

WHY ARE FACE MASKS INEFFECTIVE?

Many people don’t follow proper health etiquette while wearing a facial mask, Williams said, which essentially negates any benefits a mask could’ve had.

“I see people wearing the mask, and then they’re handling stuff and they put their hand in the mask and touch their mouth,” Williams said. “The mask may not be cleaned on a regular basis so you actually may be re-circulating stuff.”

He acknowledged that the masks “may give that person some solace,” but stressed that there is no medical need for a healthy person to wear a surgical mask in public in Ontario.

It’s believed that the coronavirus is spread the way many respiratory illnesses are: by droplets when an infected individual sneezes or coughs. This means it’s more likely for a person to become infected if they have close, continuous contact with someone who is already infected, as opposed to passing a sick person on the street.

Dr. Sohail Ghandi, president of the Ontario Medical Association, told the Canadian Press that “handwashing is more effective than face masks with this particular virus, particularly if you’re not infected.”

Hota echoed these concerns, telling CTV News on Monday that since a virus can easily be spread by touching a surface a sick person has coughed on and then touching your own face, it’s significantly more important to wash your hands frequently, and avoid touching your eyes, nose and mouth.

According to Dr. Eileen de Villa, Medical Officer of Health for the City of Toronto, the best thing people can do if they are feeling ill is simply to stay home, and to seek medical attention if symptoms worsen.

If a sick person needs to travel on public transit, observing sneezing and coughing etiquette by coughing into an elbow and turning away from other passengers is important.

Officials have stressed numerous times that the risk to Canadians is low.

Williams reiterated in Monday’s press conference that the newest presumptive case in Canada is unsurprising as she is the wife of the man who was the first confirmed case in Canada, and both of them recently returned to Toronto from Wuhan, the Chinese city at the heart of the outbreak. The biggest risk factor for this disease is having travelled to the affected areas in China.

Hota’s advice to the public is to avoid the kind of panic that drives people to buy 40 surgical masks at their local drug store.

“Panic is never helpful in a situation like this,” she said. “These are two cases. We’re watching things closely, and we’re doing what we needed to do to try and contain things over here. And that’s what our jobs are.”