Coronavirus-infected fitness enthusiasts could turn gyms into hotbeds for the disease, a doctor says.

Dr. Norman Swan told Australian outlet ABC that the sweat of people with the virus could easily spread the bug to others at workout hubs.

“Dampness is a bad thing for spreading germs,” Swan told the outlet. “You’ve got these big blokes pumping away and you never know, one of them might be a super spreader.”

“Super spreaders” are coronavirus carriers who spread the illness to a disproportionately high number of people, the Telegraph reported. While some individuals might infect one or two people, a “super spreader” may pass the illness to dozens.

But while Swan suggested that people should steer clear of the gym altogether, he said contagion could still be avoided if they take precautions.

“It doesn’t mean you stop going to the gym, you’ve got to be super careful at the gym,” Swan said. “You’ve got to make sure you wipe down before and after use.”

Health officials have cautioned against close physical contact, such as shaking hands, and suggested that anyone who experiences flu-like symptoms stay home.

Across the world, the virus has spread to more than 118,000 people, causing at least 4,291 deaths.