No, drinking hot lemon water, breathing in steam and gargling with salt water will not protect you from getting COVID-19.

These are just some of the many misleading and false claims about remedies or ways to prevent infection that have been shared to millions of people since the coronavirus outbreak began.

"A lot of people [are] floating home remedies, trying to make a profit out of this," says Dr. Sander van der Linden, a social psychology professor at Cambridge and creator of the Bad News game, a simulation that helps participants learn how to spot fake news.

Consider the motives, he says.

"I think a lot of the health stuff is people trying to dupe other people to make money off of this situation."

CBC News readers have asked us to fact-check many claims about so-called cures that are floating around social media. Here are some of the common ones:

MYTH 1: Lemons prevent COVID-19

Lemon slices in hot water won't prevent you from getting COVID-19. (Mr. Healthy/YouTube/CBC)

A Facebook post and a video with a robotic voice-over both cite the expert advice of Chinese researcher Jiao Shenme Minzi. The first clue is his name, which can roughly be translated from Mandarin into "What is your name." Minzi doesn't appear to exist, nor does the university where he purportedly works.

The video then claims that lemon in hot water "destroys the virus and cures the flu." It attributes this to Prof. Chen Horin at the Beijing Military Hospital. An institution of that exact name does not appear to exist, and neither does Horin.

"It's very easy to blind with credentials," says Jonathan Jarry, a biologist at McGill University, using names of doctors and institutions that may or may not exist. "But if something is indeed true, you would expect public health agencies to embrace these ideas."

MYTH 2: Steam and heat kills the virus in your body

One video claims you can use heat on your nasal area to kill the virus. Experts say while heat can sometimes be used to kill viruses on surfaces, it doesn't work when the virus has already infected you. (Facebook/CBC)

One such video quotes a Dr. Dan Lee Dimke, author of a 1984 book titled Conquer the Common Cold & Flu. According to his "about the author," he is not a medical doctor, but he claims to have become a lecturing astronomer at age 10 and a college teacher by age 17, and to have the ability to read 25,000 words per minute.

The video says coronaviruses are vulnerable to heat, and claims the virus only lives in the coolest part of your body, which it identifies as the nose and sinuses. It recommends breathing in hot air from a hair dryer or in a hot-weather locale.

Jarry, who specializes in communicating science, says it can be difficult to discern that the video's main claim is false.

"In a lot of these pseudoscientific videos, there is a kernel of truth. There's something there that is true, and it is true that viruses can be inactivated using heat," said Jarry, noting there's some evidence that steam vapour can disinfect surfaces.

"But there's a very big difference between sanitizing a surface and sanitizing yourself, because the virus is not just waiting … in your nostrils. It's further down your airways."

MYTH 3: You can make your own N95 mask

It's not possible to make your own N95 mask at home out of a bra. While you can make a mask for your face, a bra cup can't filter out minute particles the way an N95 mask can. (Rebecca Brand/YouTube/CBC)

People are circulating do-it-yourself video tutorials, including one 20-minute-long instruction on turning a bra into a supposed N95 mask that's been viewed more than a million times on YouTube. It was made by a woman who has dozens of other videos on recipes, dieting and beauty tips.

At one point she claims, "Natural materials like cotton and wool naturally repel viruses. I had to find that out on the internet!" There is no evidence that claim is true.

She provides no sources for her information and doesn't warn her audience that her method would not be as effective as an actual N95 mask.

She concludes by saying, "I think this might really help a lot of people."

But good intentions can be dangerous, van der Linden says.

"Perhaps somebody who honestly thinks that they're contributing by doing something useful is actually spreading misinformation in the sense that these masks won't help people. And if they do think they help them, they go on to get sick. And so it could have serious consequences," he says.

WATCH | Experts warn about products claiming to cure, prevent coronavirus

From standing on your head, to drinking a special herbal tea -- experts are warning Canadians against falling for phony cures for COVID-19. 1:54

There may not be consensus on whether a mask of any kind could provide some measure of protection, but Dr. Jen Gunter, an obstetrician-gynecologist who frequently debunks pseudoscientific medical claims, says homemade masks can't compare to an actual N95 mask, even if they are similar in shape to a bra cup.

"It's nothing to do with the shape. You know, N95s filter out at least 95 per cent of particles that are [larger] than — I think it's point three microns," she said. "And the fabric that's used in them, the very specific mesh, is very difficult to make."

MYTH 4: A breath test can detect coronavirus

A picture of a sheet of paper that offers a simple test for COVID-19: holding your breath for more than 10 seconds. (Facebook)

A printed sheet of instructions lays out how to test yourself for coronavirus infection by holding your breath, and encourages readers to perform the daily test created by "experts" in Taiwan.

The paper claims that if a person can hold their breath for more than 10 seconds without coughing or discomfort, that's proof there is no infection.

"If it were that simple, we wouldn't be hearing on the news day in, day out that we are running out of test kits for COVID-19," Jarry said. "If you can successfully hold your breath, you could still have the virus and be contagious."

"And again," Gunter said, "apart from the fact that that's incorrect, this makes other information about the virus harder for us to get out to people."

MYTH 5: Drinking warm water, gargling salt water can protect you

This forwarded email urges people to repeatedly drink water or gargle throughout the day to unblock their airways and prevent them from getting sick. (CBC)

A chain email is going around attributing a list of things you can do to protect yourself — like drink warm water every 20 minutes and gargle with salt water — to a friend of a friend who is "connected in China health care."

The email claims you have to regularly unblock your airways by drinking liquids to keep yourself safe.

Using the old method of a chain letter, these types of messages spread easily among friends on WhatsApp or Facebook "because a person who is giving you the information is already somebody that you trust," said Jarry.

But, he added, "If you don't know who the actual primary source is, it's very difficult to assess the accuracy."

These recommendations, says Gunter, are "absolutely not true."

"But I can see when there's so much uncertainty how something that's almost a bit ritualistic ... could make people feel comfortable. And the problem is, is when there's nothing to do except hand-washing and stay inside, that people look for something concrete to do."

How to evaluate COVID-19 advice you spot online

First, pause. Don't share anything, especially out of fear, before you have had a chance to evaluate the claim. Take a look at where the information is coming from. Texts from "friends of friends" or unnamed hospital workers are likely to contain false information. Google it. You can enter the words you're interested in searching, like "lemon water and coronavirus" and the words "fact-check" into a search engine and see what you get for results. Often claims have already been debunked and you will be able to find those results quickly. If it sounds too good to be true, it likely is. There is, as yet, no approved drug therapy or vaccine for COVID-19. Also be skeptical of products and practices that claim to boost immune function or detoxify your body or organs. Check the names and credentials of people cited as experts. For example, it's easy to verify that Dr. Theresa Tam is Canada's chief public health officer. But sometimes so-called experts are speaking outside their area of expertise. Is a physicist giving you information about mask wearing? They may not be a reliable source of information. When in doubt, don't share information. You may be spreading misinformation and causing others to panic needlessly.

CBC's COVID-Check unit is here to help you sift through the noise and get to the truth. If there is something you want us to check out and verify, contact us at covid@cbc.ca.