HANOVER — Upper Valley schools continued efforts to limit the risk of spreading the novel coronavirus for staff members and students on Tuesday, as several colleges around the country moved to cancel in-person classes and Dartmouth College shuttered dorms for an upcoming break to assess its approach to COVID-19.

Dartmouth on Tuesday announced it would limit on-campus events to 100 attendees through April 17, and suspended admissions tours beginning Friday.

And on Tuesday evening, a community-wide email from Provost Joseph Helble asked undergraduate students to vacate their dormitories as soon as their final exams end this week to minimize the risk of transmission, and for others who had been planning to stay over spring break to leave by Monday, March 16, with “only a very few exceptions” for students with visa issues or “known high-need medical or other circumstances.”

“While it remains our intention to hold spring term on campus as planned, we will be using the interim period to assess the situation and make a determination as to the best way to provide educational continuity for our students,” the email said.

In addition, Dartmouth recommends that people practice “social distancing” by maintaining at least 6 feet between themselves and others; wash their hands; avoid handshakes; and stay home when sick. The college also has crafted a plan for addressing potential scenarios and responses; pay continuation; job protection; and temporary alternative housing requests to allow faculty and staff to work remotely if necessary.

Dartmouth Dean of the Faculty Elizabeth Smith and Helble sent a survey to faculty to assess which courses could be taught online to meet the needs of students who had been planning to be off-campus spring term and for students who may be required to quarantine during the semester.

Some in the community took to Twitter to voice concerns that Dartmouth was not following in the steps of some of its peer institutions such as Columbia University in New York and Harvard University in Cambridge, Mass., in moving to online-only classes to minimize the risk of transmitting COVID-19.

Dartmouth Associate Professor of English and creative writing Jeff Sharlet said he would leave the decision of what to do to public health experts.

“But if Dartmouth takes a different path than similar institutions telling students not to return from spring break, I’d like to know more about why,” Sharlet said in an email on Tuesday.

Sharlet said that although he looks healthy, he has had two heart attacks and has heart disease.

“From what I’ve been able to learn, (I) fall into a category with a mortality rate nearly equivalent to that of an octogenarian,” he said. “I’m mostly healthy otherwise, look healthy, but maybe that’s the point — we can’t make assumptions about who’s really at risk.”

Dartmouth wasn’t the only Upper Valley school adjusting to the virus.

The Waits River Valley School in East Corinth canceled classes on Tuesday to give staff time to disinfect the school as a Vermonter with ties to the school community was being tested for COVID-19 and after several staff members and students had been out with flu-like symptoms and a viral stomach bug, according to the Monday message to the community, provided to the Valley News by Orange East Supervisory Union Superintendent Emilie Knisley.

“This person has not had contact with the school and the risk is very low, but we feel that a deep cleaning is an appropriate precautionary measure to take at this juncture,” the email said.

Administrators said they expected the school would reopen for classes on Wednesday.

New Hampshire health officials announced a fifth case of COVID-19 on Tuesday.

The man from Rockingham County is self-isolating at home, according to a news release from the New Hampshire Department of Health and Human Services. He was tested by the Massachusetts Department of Health after coming down with symptoms following contact with someone else with the virus, which was first identified in Wuhan, China, late last year.

This is the second case in Rockingham County. The first, which was announced on Sunday, was an individual who had traveled to Italy, one of the hotspots of the outbreak.

The other three cases in New Hampshire involve Grafton County residents, the first of whom developed symptoms following a trip to Italy. The second patient, like the first, is a Dartmouth-Hitchcock Medical Center employee. The third, which health officials announced on Sunday, is someone believed to have contracted the virus from the second patient, before he developed symptoms, at Hope Bible Fellowship in West Lebanon on March 1.

All 60 people who attended a service or coffee social at the church that day have been asked to self-quarantine for 14 days, the length of time health officials believe it takes for symptoms to develop.

The state is monitoring 228 people for symptoms, and tests are pending for 10 additional people; 53 people have tested negative for the disease, NH DHHS said Tuesday.

In Vermont, one person in Bennington County has tested positive for the virus. Vermont officials are monitoring 226 people for symptoms, according to the Vermont Department of Health.

Education and health officials in the Twin States sent out guidance Tuesday for schools to use in evaluating whether to cancel school trips or to close schools due to the virus.

In New Hampshire, officials recommend that school trip planners consider the level of risk in the area being visited, the mode of transportation, the number of people in attendance at planned activities, whether the students and staff members have health issues that might make them more vulnerable to the virus, and whether the trip could be rescheduled.

In Vermont, health officials advised schools to close in consultation with the Vermont Department of Health if “a child, staff member, administrator, or family child care household member has been diagnosed with a confirmed case of COVID-19.”

Officials also emphasized the importance of preventive measures such as posting information, performing routine cleaning, and having people who are sick or have traveled to hotspots stay home.

At Colby-Sawyer College in New London, President Sue Stuebner said school officials are developing contingency plans should the virus hit close to home, but so far the school has not had to put those plans into action.

“We’re really kind of in that information-gathering stage,” Stuebner said.

The school has a low-occupancy residence hall that could be used to quarantine students should the need arise. It also has the ability to move to online-only classes if necessary, but only intends to make such a change if there is a case on campus or “a proliferation of cases” in the county, she said.

“Our preference is to try and stay open as long as possible,” Stuebner said.

Colby-Sawyer is in Merrimack County, which has not yet seen any cases of COVID-19, Stuebner said. Though some students are in training at DHMC, Stuebner said the students were not members of the “first-response team” that would be treating COVID-19 patients.

Two Colby-Sawyer students recently returned home from study abroad trips in Italy and will finish their coursework from their homes, she said.

Students return from spring break this weekend, and Stuebner said she aims to make it through the next six weeks to graduation. Even so, she said, the school is ready to make adjustments as needed and to “err on the (side of) safety of our community.”

At Vermont Technical College based in Randolph, President Patricia Moulton said her school has provided hand sanitizer and disinfecting wipes to school staff. Vermont Tech also is planning in case in-person classes need to be canceled. Moulton said the school is determining how more classes might be offered online, but she noted that the school operates a farm with animals, and other courses also require hands-on work.

“Our education is so applied and hands-on,” she said.

Vermont Tech officials also are asking staff members and students to let them know where and when they’ve traveled, even if the point of travel is not yet a place with travel re strictions, Moulton said.

“We want to have a sense of ‘Where did people go?’ ” she said.

Vermont Tech has canceled all international trips and is analyzing domestic trips on a case-by-case basis, she said.

Nora Doyle-Burr can be reached at ndoyleburr@vnews.com or 603-727-3213.