TORONTO -- Goblins and ghouls keen to trick-or-treat should wear a cloth mask rather than relying on a Halloween mask to protect them from COVID-19, according to health officials with the Mayo Clinic, adding that doubling up on masks could lead to breathing problems.

The advice comes as health officials in Ontario advise against trick-or-treating in the province’s hardest-hit cities, including Toronto and Ottawa. But Canadian doctors are conflicted over whether trick-or-treating poses a genuine risk to children as most provinces are allowing the door-to-door tradition to proceed.

For those planning their costumes, it’s important to factor in how a cloth mask should be properly worn, according to Dr. Nipunie Rajapakse, a Mayo Clinic pediatric infectious diseases specialist.

"A mask as part of a costume would not be considered to be protective against transmission of infection,” Rajapakse said in a statement.

Instead, cloth face coverings should be worn as they normally would be. Wearing a cloth mask under a Halloween mask is discouraged, she said, because it can impair a child’s breathing.

"There are some nice Halloween prints that they're making now, but we are discouraging wearing them underneath a costume mask,” she said.

Some mask-makers have created special Halloween-themed masks that double as costumes, including prints inspired by films such as “Silence of the Lambs,” “Friday the 13th” and “Hocus Pocus.”

The Mayo Clinic, which is based in the U.S., is advising against trick-or-treating altogether, saying the risk of transmission is too high. But health officials in most parts of Canada say the tradition is OK, as long as certain guidelines are followed.

Chief Public Health Officer Dr. Theresa Tam has said trick-or-treating is a low-risk activity as long as participants practice physical distancing. Those handing out candy should consider creative solutions, she said, such as using a hockey stick to drop candy into bags.

Tam also suggested that households pre-package treats and advised against large bowls that require kids to “rummage” for candy.

In Ontario, health experts recommended that people in COVID-19 hotspot regions of Ottawa, Toronto, Peel and York should skip trick-or-treating this year and find new ways to celebrate the tradition at home.

So far, the rest of the country has not followed suit.

British Columbia health officials say trick-or-treating in small groups can be safe. Alberta officials also say trick-or-treating is OK but — contrary to advice from the Mayo Clinic — say a non-medical mask should be worn underneath costumes, so long as breathing is possible.

Manitoba, Saskatchewan, Quebec, Nova Scotia, Prince Edward Island, Newfoundland, Yukon and Northwest Territories have all given the green light to trick-or-treating. In New Brunswick, trick-or-treating is allowed everywhere except the province's orange zones, which currently includes the Campbellton region.

But Prime Minister Justin Trudeau said his family plans to follow Ontario’s guidelines and skip trick-or-treating this year.

"I think it’s really important that Canadians across the country listen to their local health authorities. We know that it’s not easy, and it’s frustrating, and we’re trying to get through this pandemic as best we possibly can and to do that we have to reduce community transmission," said Trudeau during a press briefing in Ottawa on Tuesday.

In an interview with CTV News Channel earlier this month, CTV News Infectious Disease Specialist Dr. Abdu Sharkawy agreed that trick-or-treating is "extremely low risk,” but that Canadians should still respect guidelines from public health authorities.

"Let’s remember that this is one of the few occasions that can almost exclusively be experienced in an outdoor setting. We know from the science of transmission of this virus that the risk is incurred by being indoors in poorly ventilated areas, areas in close contact with others for prolonged period of times. I struggle to think how this is something we need to worry about," he said.

With files from Alexandra Mae Jones​