“We’re living off her tips,” she said of her family. “It was a difficult decision, but honestly we weren’t really left with a choice.”

Harvard officials said they were swamped with requests for financial and logistical help and could not take time to talk in detail about the situation. They noted that Gov. Charlie Baker of Massachusetts had declared a public health emergency on Tuesday, and said that the university had been forced to respond in kind. But they said that any students who were on financial aid and had a “demonstrated need” would be taken care of.

By midday Wednesday, as the pressure built, the university had put out written guidelines for students who receive financial aid, offering to help cover the costs of storing and shipping their belongings. The university said it was stationing staff in dining halls to help with travel booking, and that the amount of financial aid that students were receiving would determine how much of their travel costs Harvard would cover.

More than a thousand miles away, at Iowa State University, Alex Stein, a 19-year-old sophomore, was astonished and a little freaked out when the teachers and teaching assistants all wore gloves as they handed out a test on Tuesday night in his mechanics of fluids class. “They were scared of getting it while passing out the exams,” he said.