SAN FRANCISCO — The thought of getting on a plane is far from most people’s minds at the moment, as they shelter in their homes. But some people have no choice but to fly now, whether it is returning from a long trip or rushing to leave a country as a visa expires.

In the days of the coronavirus, travelers are often taking extreme precautions to protect themselves. They wear anything from plastic ponchos to laboratory goggles to biohazard suits. They wipe down tray tables and arm rests with disinfectant. Some passengers say they avoid using the lavatory, even on long transcontinental flights, believing there is a higher risk of infection there. Many pack their own food, and keep their protective gear on even as they sleep.