This city’s convention center typically draws vibrant crowds for trade shows and exhibitions, but seemingly overnight it now looks ready to handle a pandemic.

Row after row of hospital beds line the 50,000-square-foot floor. Cabinets along the perimeter hold critical drugs and medical supplies. A trailer of portable showers stands at one end of the room, a movable X-ray machine at another.

This MASH-style field hospital in the DCU Center will be ready to accept its first patients Thursday — one of three pop-up hospital sites to treat the fast-rising numbers of people in Massachusetts sickened by coronavirus.

A larger site at the Boston Convention and Exhibition Center in the Seaport is also expected to be ready this week, though it’s not yet clear when the location will accept patients. A third site is planned for Joint Base Cape Cod.

The pop-up hospitals are designed for people who have tested positive for COVID-19 and are sick enough that they need to be monitored by doctors and nurses, but not so ill that they need critical care. By treating less acute patients at these sites, hospitals will have more space to treat seriously ill patients, including those who need ventilators to help them breathe.

The Boston field hospital will have 1,000 beds, half of them designated for the homeless. Partners HealthCare is managing the site and is seeking volunteers to sign up for 12-hour shifts at the convention center.

Cape Cod Healthcare will manage the Cape location but has not said when it will be ready.

“This work is incredibly important because our modeling predicts an increase in the number of patients that will need medical attention or post-acute care in the coming weeks,” said Brooke Karanovich, spokeswoman for the state’s Executive Office of Health and Human Services. "More than 20 other states have set up field medical facilities or other alternative care sites.”

The rapid effort to build the Worcester field hospital involved hundreds of people from city, state, and federal agencies, and the private UMass Memorial Health Care system. It began last week when beds and other supplies from the federal government arrived, and members of the Massachusetts National Guard began assembling them. Staff from UMass Memorial have been supplying the medical equipment.

“It looks different, feels different in here,” said Dr. John Broach, a disaster medicine specialist at UMass Memorial and medical director for the Worcester field hospital. “But in terms of medical care, we’re planning on making it identical [to] care that people receive in the hospital.”

While traditional hospitals are not yet full, these field hospitals are critical to the state’s strategy of increasing capacity to manage the expected surge in patients. State officials expect these locations will add 1,500 to 2,000 beds.

Field hospitals have been part of the strategy in other hard-hit areas, from Wuhan, China, to New York City. In addition to treating patients who need hospital care, the sites can serve as observation units for patients who are recovering from the virus but not yet ready to go home.

“The creation of field hospitals is an important piece of the puzzle in generating overall capacity,” said Dr. Thomas Tsai, assistant professor at Harvard T.H. Chan School of Public Health.

Tsai and his colleagues have projected that Massachusetts could see a surge of coronavirus patients that far surpasses the number of hospital beds in the state — but the models don’t account for changes over the past few weeks to increase hospital beds and to slow the spread of the virus through social distancing.

Individual hospitals have also taken steps to expand capacity, particularly for patients who need intensive care, for example, by converting recovery rooms into intensive care units.

“The hope is that we may never see the surge that will require us to use the field hospitals, but it’s important for us to have them in place, because there’s a lot of uncertainty around the hospitalization rate,” Tsai said.

In Worcester, the convention center was transformed in about 10 days. The site has 216 beds — metal cots with slim black mattresses — each in a 10-foot-by-10-foot square. Thin black screens serve as walls to give patients some privacy. There is no natural light. The setup is spare, though staff are working to provide patients some small comforts, such as iPads to help them pass the time.

Turning an exhibition hall into a hospital involved several logistical challenges, including how to provide oxygen to patients and how to monitor their vital signs. UMass Memorial officials hired contract workers to install oxygen tanks outside the building and pump the oxygen through tubes to the patients inside. They purchased wearable biosensors that will allow nurses to keep track of patients’ heart rates on Bluetooth-connected screens.

The vast room has been converted so it has negative air pressure to control the spread of germs.

Computers were delivered from empty wings of UMass Memorial Medical Center, a couple of miles away, where elective surgeries and nonurgent appointments have been canceled. Meals will be cooked at the medical center and delivered to the DCU Center. Colorful signs, marking patient units and nurses’ stations, came from a local print shop.

Dr. Eric Dickson, chief executive of UMass Memorial Health Care, estimated the nonprofit health system is spending at least $10 million to set up the site.

None of it would matter if the hospital could not find enough health care professionals to work here. But so far, officials are confident they have enough staff — a combination of doctors and nurses from UMass Memorial, nursing students, medical students and recent graduates, and recently retired health care workers.

“We got 1,000 people who volunteered to work for us,” Dickson said during a visit to the field hospital this week. “I thought this was going to be a bigger problem.”

As many as 200 workers will staff the site during each shift — if it fills up. They all will wear protective equipment, including masks, gowns, and gloves, when they’re around patients, in the area known as the “hot zone.”

The facility will have a few ventilators and paramedics experienced with intubation in case a patient’s condition deteriorates. Anyone who needs to remain on a ventilator would be transferred to a nearby ICU.

Worcester city officials initially considered using the student dorms at Worcester State University as a potential hospital site, but they quickly dropped the idea. Patients would be behind doors and across different floors, making it difficult for health care providers.

Hospital and city officials concluded that the city-owned DCU Center, with its open layout, would be the best option. The Baker administration backed the plan.

The project has required public officials and health care providers to make quick decisions without dwelling on the details of how to divide responsibilities or costs. For example, they hastily purchased a generator to ensure the field hospital would have a backup power supply.

"I don't know who's paying for the backup generator. I don't know if I'm paying for that, or somebody else," said Worcester City Manager Edward M. Augustus Jr. "We approached this as: 'Just do it. If this is what has to be done, just do it.' "

“We wanted to get this thing done and be ready,” Augustus said, “before the peak hit.”