The actions are meant to keep the living from congregating around the dead and dying. And nowhere is that principle more strictly enforced than in hospitals.

Intensive care units in the city once saw a steady stream of visitors. Nurses and doctors learned about their patients through them: which patient had the spouse who spent every waking hour at the bedside, which patient had the large family.

Now bedside vigils, and visitors generally, are a thing of the past.

In recent weeks, an exception has sometimes been made when a patient is on the verge of death. But even then, the visitor is usually not allowed in the actual room.

In one Manhattan emergency room, a woman recently stood by the secretary’s desk. A doctor handed her a phone. “I love you,” she said. “Things will be OK.”

The words were played through the call bell in her husband’s isolation room, 20 feet away. He was in a medically induced coma, dying. They had been married 40 years, according to a hospital employee who described the scene.

Dr. Dylan Wyatt, a resident physician at NewYork-Presbyterian Brooklyn Methodist Hospital, said one recent image is seared into his memory: a woman who had been summoned to the hospital because her mother, in her 90s, seemed close to death.