For the past two months inventor Yezin Al-Qaysi has been riding the Toronto subway in Canada wearing a huge black "mad helmet".
The hazmat (hazardous materials) helmet completely encloses his head and upper torso, and has a visor that extends all the way down to his chest.
On the back is a battery-powered fan and filter respirator system that purifies air that is sucked in, and pushes "stale" air out.
Looking like a dystopian figure straight out of an apocalyptic movie, the 32-year-old unsurprisingly gets some strong reactions.
"Somebody screamed: 'Where did you get that!' and many people approach me out of curiosity," he says.
"Others are amazed.. They certainly don't laugh, but even if they do, I cannot see their mouths because everyone is wearing masks."
Mr Al-Qaysi is one of a number of designers and entrepreneurs around the world who have rushed to release hazmat, or PAPR (powered air purifying respirator), helmets this year, aimed at people looking for more protection against coronavirus than just wearing a face mask.
His is called the BioVYZR, and the battery is said to last for up to 12 hours. The Canadian says that his business - VZYR Technologies - now has sales in the "tens of thousands" mark.
US Navy veteran Chris Ehlinger, is another hazmat helmet creator.
"These helmets in a sense psychologically prepare us for the future destiny of our species," says the 35-year-old.
His company, Valhalla Medical Design, based in Austin, Texas, has launched a product called NE-1, which looks similar to a motorcycle helmet. In addition to a powered air filtration system, it has internal and external microphones and speakers, so that the wearer can more easily speak to people around him or her.
It even has Bluetooth audio built in, so you can make a phone call or listen to music.
But with a coronavirus vaccine having been announced last week, are helmets like these really necessary?
Michael Hall, whose firm sells a PAPR helmet called Air, believes they will be popular in the longer term with people concerned about bad air quality.
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His company, Utah-based Hall Labs, says it has sold 3,000 so far. It is also now working on more high-tech versions, where the visor turns into a screen on which the user can watch videos.
"And for airline travel we'll be able to create a segment [with helmets that work] like noise-cancelling headphones," says the 44-year-old. "We think that there's a market for that kind of serenity."
Yet whether for protecting against airborne viruses or bad air quality, are such helmets a bit over-the-top?
Natasha Duwin, whose Florida-based firm Octo Safety Devices makes face masks, says she can see the appeal.
"Helmets have the advantage that they show people's faces," she says. "You can see smiles and human expressions, and have a very strong sense of security.
"Yet because each one of these helmets depends on at least two filtration systems, batteries, and [other things], all these items can break down. And if only one of them breaks down, you are in serious trouble."
She also cautions that the helmets will need to be thoroughly cleaned before each use.
Ms Duwin says that for most people, all they need is a fitted, respirator mask that meets the certified quality standard in that country. Respirator masks have inbuilt filters, and both fit more tightly, and work more effectively, than simple fabric face masks.
The above three helmets cost in the range of $149-$379 (£113-£288), but none has yet to receive certification. However, each of the three firms say they are nearing the final stages of the process.
Dr Suzanne Pham, medical director of the Covid-19 response team at Weiss Memorial Hospital in Chicago, says: "It remains to be seen if these fascinating helmets effectively battle Covid, as currently there is not enough research behind them.
Dr Pham is also concerned that the helmets could lead to a societal division. "It will create a split in society between those who can afford something that seemingly might protect them more, and those who cannot.
"And with those who cannot being left feeling like, 'Oh, am I being under-protected by wearing just a surgical mask?'"
However, she does think that the helmets will sell well, as much for the confidence they give the wearer as the actual protection they offer. "After all, the pandemic has been first and foremost medical, but also psychological, absolutely."