Doctors have confirmed the first positive tests for coronavirus cases among Mount Everest climbers, The New York Times reports. This month, three travelers were flown off the mountain after complaining of COVID-like symptoms. At least one of them has tested positive, officials say. Since reopening the mountain to climbers this year, more than 370 climbing permits have been issued, and that number may increase, tourism officials say. In order to climb the world’s highest mountain, mountaineers must stay at the Everest base camp for roughly two months to adapt to the high altitude, and officials are now making sure groups of climbers aren’t mingling with each other. To prevent an outbreak, Nepal’s government has so far mandated mask-wearing, social distancing, and regular testing provided at a makeshift health-care unit at an altitude of 17,600 feet.

Mingma Sherpa, the chairman of Nepal’s largest expedition operator, said that climbers will still continue to venture to the top, even if they test positive. “Expeditions won’t be canceled,” he said. “There’s no point of returning or giving up climbing after reaching base camp.”