In between teaching two of her classes, Lisa Steichmann got an ultrasound to check whether cancer had spread to her lymph nodes. After losing four organs to the disease in the past decade, she was relieved by the results. But it was only the first of a series of high-stakes tests on her mind: She scheduled 12 coronavirus tests, one each week this semester. Despite her requests and a doctor’s note warning of the specific danger the disease poses for her, she had not gotten permission to teach fully remotely when classes started this fall, she said.

“Everything in me says you’re heading into danger, like a first responder heading into fire,” Steichmann said. She saw students crowding the halls. She knew more than one of the students in her classrooms had already tested positive by mid-September. But she’s 65 years old and needs the health insurance and the retirement benefits she’s accruing at the University of Michigan, she said.

“I really hope I don’t cry in front of my students,” Steichmann said. “I can’t tell them I’m terrified.”

As students have poured back into classrooms, dorms and football stadiums across the country amid the pandemic, some faculty members have felt a mounting sense of alarm.

Spring was marked by optimism: With vaccinations widespread and cases decreasing, many people were eager for a return to normal campus life. Then the delta variant came roaring in. And despite increased precautions at many campuses in the summer before students returned, the reality on the ground has hit some faculty members hard as they face crowded rooms full of unmasked students, or see the numbers of cases spiking.

“The pressure was building all summer long,” said Irene Mulvey, a professor of mathematics at Fairfield University in Connecticut who is president of the American Association of University Professors (AAUP), and concern is widespread. Faculty in many places have been pushing for more protections for weeks or months. “Now that people are back in the classroom, they’re worried about their safety, they’re worried about bringing the virus home,” to children too young to get vaccinated or to immunocompromised family members. “People are really frightened now that we’re back on campus.”

Faculty members have signed petitions, passed resolutions, written open letters calling for more precautions and more options.

Some have protested. There were rallies and marches at multiple campuses last week within the University System of Georgia, and others are planned at campuses in Kentucky, South Carolina and Texas, according to the AAUP. At the University of Oklahoma on Tuesday, faculty members rallied with signs calling on the school to do more to protect them.

Some have defied university rules, requiring masks or switching their classes to online. Some have launched job searches, with an eye toward places with more safety measures. And some people have resigned.

Not everyone is worried. Some professors have pushed back against mask and vaccine requirements, arguing that individuals should be free to decide. Some faculty members are satisfied with their school’s coronavirus protocols, or dismissive of the risks. Many are enjoying seeing students back on campus. But for others those scenes are fraught.

“It’s like watching puppies play when you’ve been walking through a cemetery for two years,” Steichmann said. She loves her students. “I desperately want to be around them. But I can’t risk my life.”

Last week, news of a tentative agreement between the lecturers’ union and the university gave her real hope that she might be able to teach all of her classes online this fall.

Then she got an email from university officials telling her of multiple changes they had made to make her classrooms safer — and that most of her classes would be reassigned if she didn’t teach in person.

“While we can’t talk about a specific employee situation, we can say only a handful of medically supported concerns were raised,” Kim Broekhuizen, a spokeswoman for the university, wrote in an email. “Classrooms have not been associated with COVID-19 transmission due to the university’s masking requirement, high vaccination rates in the U-M community and ventilation standards.”

The University of Michigan requires students, faculty and staff to be vaccinated.

At campuses across the country, there is worry that the plans laid in the spring are too risky now. That fear is most acute in places where mask and vaccine mandates have been banned by state leaders.

“In the summer, I was very excited to get back in the classroom,” said Will Kurlinkus, an associate professor of English at the University of Oklahoma. Then students began to move in, and he noticed that the throngs of shoppers at Target were no longer people in masks. He and his wife began to get emails from day care about covid cases. Now, he said, being in the classroom is terrifying. He’s most worried for his 2-year-old son and possible long-term effects of covid.

His wife and son moved to Illinois, where they felt conditions were less risky. He doesn’t know what his family will do long-term.

“Faculty are getting angrier and angrier,” Kurlinkus said.

The university maintains that state law there does not allow the school to require vaccinations or to require masks for students who are unvaccinated. The university strongly encourages mask use.

But Kurlinkus said that in the 200-person lecture halls he passes, typically three-quarters of the students aren’t wearing one. And a colleague told him about handing a mask to a student who arrived in class without one — and the student then reporting the professor to the university, complaining of unfair pressure to comply.

“Those stories are common,” Kurlinkus said.

“I’ve actually moved both my classes online without the permission of the university because it was way too dangerous,” he said.

Keeping OU healthy is a top priority, according to university officials, and efforts within the scope of state law have been put in place including vaccination incentives and requiring masking in class for two weeks after someone in the class tests positive.

In Alabama, Jeremy Fischer said he had advocated for months with the University of Alabama at Huntsville and the entire University of Alabama System for more stringent protocols, such as maintaining social-distancing efforts. In August, he resigned from his job as associate professor of philosophy, calling the situation a moral emergency. He wrote, “We know what it takes to protect community health and very likely save lives, and we have the ability to do it; what is lacking is the collective willingness to do so.”

“I did not want to remain at UAH and merely hope for the best.”

Lorraine Buchbinder was a longtime lecturer in history at the University of North Georgia’s Gainesville campus. But the university system’s policies “mandated us to have face-to-face classes,” she said, “and they are not mandating masks and vaccines for our students.” She hoped that university leaders would allow them the option of teaching online, at least until the latest surge subsided. When they did not, she felt they were forcing faculty to choose between their jobs and their health.

She chose health.

“I’m really very sad about this,” she said, fighting back tears in a phone conversation last month. At 69, she loved her job and hadn’t planned to retire for years. “I’m heartbroken about the fact that I was faced with this decision. … Teaching has been my identity, and I feel quite bereft right now.”

Georgia’s governor has strongly opposed vaccine and mask mandates. The university system has offered incentives for people getting vaccinations, encourages people to wear masks inside and has seen a decline in cases on some of its campuses after spikes earlier in the semester, according to a public statement.

More than 50 life science faculty members at the University of Georgia, many with expertise in the study of infectious diseases, signed a letter to the administration calling for a vaccine mandate, and stating they would wear masks and require students to do so in their classrooms until local community transmission rates improve, “despite the ban on mask mandates and the USG policy to punish, and potentially fire, any faculty taking this action.”

Greg Trevor, a spokesman for the university, responded with a written statement that pursuant to the university system’s policies, the school and its employees cannot mandate masks but that the University of Georgia will continue to strongly encourage vaccinations and masks indoors.

Miranda Brown, a professor of Asian languages and cultures at Michigan, has been keeping her family isolated because her 5-year-old daughter has asthma and is unvaccinated. Two years ago they had to take their little girl to the emergency room overnight three times in six weeks with RSV and pneumonia, she said, so they didn’t want to take any chances. Brown’s husband is home taking care of their daughter, who is doing her kindergarten classes virtually. Returning to in-person teaching this fall worried Brown, but the chair of her department and associate dean kindly helped her out, she said, for example allowing her to teach only small seminars this semester.

She wore N95 and surgical masks in class. “It was our one exposure,” Brown said.

Like Steichmann, she planned weekly coronavirus tests.

Last week, she got results: Positive.

“I’m very sad,” she said.

The contact tracer told her she most likely caught it on Sept. 8. “That was the third class I taught,” she said. “Day three. That didn’t take long.”