We’re answering your questions about the pandemic. Send yours to COVID@cbc.ca and we’ll answer as many as we can. We’ll publish a selection of answers every weekday online, and also put some questions to the experts during The National and on CBC News Network.

We’re answering your questions about the pandemic. Send yours to COVID@cbc.ca and we’ll answer as many as we can. We’ll publish a selection of answers every weekday online, and also put some questions to the experts during The National and on CBC News Network.
So far we’ve received more than 20,000 emails from all corners of the country. Your questions have surprised us, stumped us and got us thinking.
Why are we not taking people’s temperatures in public places?
In some countries, temperature checks are being carried out in public places, like grocery stores, where people are scanned with a contactless thermometer for a fever. The idea is, if someone shows signs of a fever, they are not permitted to enter, in hopes to minimize the spread of COVID-19. 
Why aren’t we doing this in Canada? That’s what many, including Liz C., want to know.
Actually, some places are. 
The grocery chain Longo’s and Tim Hortons have both announced an increase in safety protocols for their staff. Employees should be wearing masks or face coverings and will have their temperatures checked before starting each shift. 
Other places like T&T Supermarkets are taking precautions
for their customers. T&T says it started temperature checks on guests at all its locations last week. 
But is this approach effective in minimizing the spread of COVID-19?
The Public Health Agency of Canada (PHAC) says no.
“Fever is not usually the first symptom of COVID-19 and in some cases a fever never develops, so implementing measures based solely on fever detection is not recommended,” a PHAC spokesperson said in a statement to CBC News.
During the SARS outbreak in 2003, PHAC says more than 6.5 million screenings occurred at Canadian airports, of which 2.3 million used thermal scanners. But PHAC says “despite this intensive screening effort, no cases of SARS were detected using this method.”
It doesn’t seem like the provinces will be implementing this measure either.
“I don’t actually feel that temperature screening is particularly helpful,” said B.C. Provincial Health Officer Dr. Bonnie Henry last week after T&T made its customer temperature check announcement.
A spokesperson for Christine Elliott, Ontario’s minister of health, also said public temperature checks are not being considered “at this time.”
Other infectious diseases specialists in Canada see it similarly. 
“Temperature checks give a false sense of reassurance,” said Dr. Sumon Chakrabarti, infectious diseases specialist at Trillium Health Partners, because they could miss many people who have COVID-19 but are asymptomatic or presymptomatic. 
“Even if someone has a fever, it is often intermittent, and they could be in the period where the fever has gone down and the temperature check would miss it,” he added.
In fact, experts now believe that the presymptomatic period for those infected with the coronavirus is the riskiest when it comes to transmission.
“We now believe that most transmission occurs during this presymptomatic period or from individuals who have mild or no symptoms at all,” said Dr. Ilan Schwartz, infectious diseases specialist and assistant professor at the University of Alberta. “So realistically, temperature checks might detect some infections but only a small proportion.”
Not to mention  the possible risk of exposure to or from the person doing the screening, says Schwartz. 
Is there anything we can do to boost our immune system?
This question comes from Judy L., but it’s one we keep seeing in our inbox. 
Experts say despite what you might see online, there is no proven way to boost your immune system against COVID-19 other than ensuring a healthy lifestyle. 
“You’re going to see a lot of talk on the internet about immune boosters and stuff you can do,” said Dr. Christopher Labos, epidemiologist and cardiologist in Montreal. “None of it is true.”
“There’s no real way to boost your immune system apart from just generally staying healthy,” said Labos. He says that right now, eating properly, exercising daily and taking walks are the best ways to do this. 
My surgery was cancelled, when will elective surgeries resume?
Melissa P. says her surgery was scheduled to be done in Toronto, but was cancelled mid-March along with all other elective surgeries. She wants to know when elective surgeries can resume.
Elliott said Monday that Ontario is planning to bring back surgeries, prioritizing cancer operations, as part of its roadmap to reopen, but she would not specify when. Officials acknowledge they need to see a consistent reduction in new COVID-19 cases, before easing restrictions.
In the latest edition of CBC’s health newsletter Second Opinion, Adam Miller examined how hospitals are tackling the surgery backlog. (Subscribe to Second Opinion.)
CBC News estimates that close to 100,000 patients across Canada have had their surgical procedures delayed due to COVID-19, Miller wrote. 
That estimate is based on data provided by the provincial and territorial health ministries, cross-checked with benchmark data from the Canadian Institute for Health Information (CIHI) on the number of procedures performed in previous years, when surgeries were at normal volumes.  
In the dramatically scaled-back operating room activity amid the pandemic, hospitals across Canada are continuing to perform surgeries on patients who are at high risk of death or disability if they aren’t treated within days or weeks a category that includes the most urgent cancer and cardiovascular cases.
Watch the full story
or read more from CBC Health’s Nicole Ireland
on the backlog of surgeries created by the cancellations during the pandemic.
Should masks be mandatory? 
A lot of people, including Dan P., are asking us whether Canada needs to make wearing masks mandatory.
Earlier this month, European countries including Austria and the Czech Republic made it mandatory to wear masks. And the practice is common in several East Asian countries that have seen some success in keeping transmission low.
New York’s Gov. Andrew Cuomo issued an executive order requiring all New Yorkers to wear masks or face coverings in busy public places, and Los Angeles Mayor Eric Garcetti mandated face coverings for workers at essential businesses.
Masks are not mandatory in Canada, but Health Canada suggests a mask won’t hurt, “when worn properly, a person wearing a non-medical mask or face covering can reduce the spread of his or her own infectious respiratory droplets.”
Earlier this month, Canada’s Public Health Officer Dr. Theresa Tam reversed her initial advice on non-medical masks
, and now says they can add some extra protection. 
“The science is not certain, but we need to do everything that we can and it seems a sensible thing to do,” she said. 
The World Health Organization (WHO) does not officially advise the general public to use masks to prevent the virus from spreading, but recommends medical masks for health-care workers, and anyone who is sick with COVID-19 symptoms, or caring for someone who is sick. 
“Currently, there is insufficient evidence for or against the use of any type of mask among healthy people in public settings,” said a WHO spokesperson in a statement to CBC News. But WHO says it will update its guidelines once new information emerges. 
Not everyone agrees with WHO’s mask recommendations; you can read more about the debate here
The best way to prevent the spread of COVID-19 is frequent hand washing with soap and water for at least 20 seconds, staying at home if you’re sick, and practicing physical distancing.
Monday we answered questions about reopening schools and what to do if your parents get sick. 
Keep your questions coming by emailing us at COVID@cbc.ca