Born in New York City, Dr. Levitan, 58, trained at Bellevue under Lewis R. Goldfrank, a towering, pioneering figure in emergency medicine. Dr. Levitan later practiced in Philadelphia and became a teaching guru on managing the human airway — including performing the tricky but vital task of intubation, threading a breathing tube into people who are not getting enough oxygen.

The coronavirus assaults the lungs.

“This is the airway challenge of the century,” Dr. Levitan said. “I’m an airway guy. I’m not going to sit this one out.”

On Saturday, he emailed the Four Seasons Hotel, which had recently announced that it would provide rooms for visiting medical workers. But the hotel replied that it was not yet ready for bookings and that when it was, they would be managed by “local medical associations.”

(The governor’s office said on Thursday that it was working with a tourism organization in the city to set up a portal for visiting medical workers to make hotel reservations, but details were not available.)

So, Dr. Levitan turned to his older brother and his family, who were out of town and have an apartment in the West 60s near Central Park. They arranged with the building to have a key waiting for him.

When Dr. Levitan arrived on Saturday, he said he was handed a sheet listing the co-op’s rules for the pandemic — one family at a time in the elevator, dog walkers must be met in the lobby and so on. Near the top, it said: “No one except building residents; family members; nannies and home health care aides will be allowed into the building.”

Though it has nearly 300 apartments, the building was quiet. “The place is a ghost town,” Dr. Levitan said. “Anybody with money has left.”