Boston’s newest medical facility — a pop-up field hospital at the city’s cavernous convention center — has already treated more than 100 coronavirus patients in the past week and could reach capacity in the coming days as the state’s COVID-19 cases peak.

The already high demand for beds in the temporary facility known as Boston Hope is a sign of the magnitude of the pandemic, even as doctors and state officials say social distancing measures are helping to slow spread of the virus.

The site has 1,000 beds for patients with coronavirus, 500 for those who need medical care, and another 500 for individuals who are homeless and recovering from COVID-19.

“If the surge really happens, which it feels like it’s here and escalating, then in fact we will be filling all of our beds,” said Jeanette Ives Erickson of Partners HealthCare, co-director of the facility.

The temporary hospital at the Boston Convention and Exhibition Center is the largest of five field hospitals planned for the state. A 216-bed site was the first to open, on April 9, at the DCU Center convention hall in Worcester.

Two additional field hospitals are slated to open Monday, at University of Massachusetts Lowell and at Joint Base Cape Cod. Each site will have about 90 beds. The following week, another site is scheduled to open at UMass Dartmouth.

The sites are designed to treat patients who don’t need intensive care but are not well enough to go home. Many of them, for example, need supplemental oxygen.

By moving patients who are less acutely ill to these field sites, hospitals can devote more space and resources to the sickest patients, including those who need ventilators and other intensive treatment.

More than 3,700 people across Massachusetts who have COVID-19, or are suspected to have it, already have been hospitalized. Massachusetts General Hospital has the most — more than 400 of these patients — but even small community hospitals each have dozens.

“These field hospitals are crucial in reducing the strain on Massachusetts’s health care system and have helped us add a significant number of beds as we deal with the surge,” Governor Charlie Baker said Saturday at a press conference at the Boston convention center.

Field hospitals have been part of the strategy to respond to coronavirus in other areas, including New York, where Governor Andrew Cuomo said 800 patients were sent to a temporary hospital at the Javits Convention Center in Manhattan.

In Massachusetts, state officials, health care providers, and members of the military have worked to build each of these sites in just several days, transforming concrete floors and gymnasiums into MASH-style medical stations with cots serving as hospital beds, separated by curtains and screens instead of walls. The furnishings are spare, but patients have access to doctors, nurses, and medications.

“It’s working pretty much exactly the way it was intended to work,” Baker said of the Boston site. “That’s a big big relief as we move forward through the surge.”

The state’s hospitals still have the capacity to treat additional coronavirus patients — as well as those with other urgent medical issues, he added.

Boston Hope admitted its first patient on April 10, the day it opened. Patients have come from hospitals across the Boston area, either from emergency departments or after an inpatient stay. When hospitalized patients start to recover and are no longer considered “acute,” they can be moved to the field hospital.

“Having this site … allows our hospitals to focus on the really sick,” said Erickson of Partners HealthCare, which is managing medical care at the facility. “The data indicate that the volume of intensive care unit patients is increasing.”

On Saturday, Boston Hope had 152 patients, 91 on the hospital side, and 61 on the respite side, which is for the homeless.

Hundreds of health care workers from Partners and other organizations are staffing the field hospital, including some who were furloughed from their regular jobs during the pandemic, Erickson said. Dozens of clinicians from the US Army Reserve are also working at the facility — and hiring is ongoing.

The field hospital in Worcester had a high of 10 patients during its first week. Some were discharged home while others were moved to UMass Memorial Medical Center because their conditions worsened.

“We haven’t had any really big unanticipated challenges,” said Dr. John Broach, medical director for the Worcester site. “I think the planning has really paid off.”

Only one 40-bed unit at the DCU Center was staffed and open during the first week, but Broach expected that to change. “We’re anticipating as we get into the teeth of this thing … those beds will be in high demand,” Broach said. “It’s been steadily increasing, and we’re expecting it to increase more.”

Doctors and nurses at the Worcester site are trying to reduce the need for personal protective equipment, such as respirator masks, gowns, and gloves, by communicating with patients by phone when possible, instead of entering the patient’s room for each check-in.

Officials at Lowell General Hospital are watching the experience in Boston and Worcester as they prepare to open a hospital across three basketball courts in the UMass Lowell recreation center. They will be ready to open the first 14 beds on Monday but need to find more staff before they can open additional beds, said Amy Hoey, chief operating officer.

Dr. Nathan MacDonald, chief of emergency medicine at Lowell General, said it’s difficult to predict how many patients will need to be admitted to the site.

“It’s ready to be deployed once we’ve filled all of the resources at the hospital,” he said. “That’s the strategy first: to use every last bed we can at the hospital before we use this space. But we think it could be a very safe, effective way to care for those patients really in the last few days before they go home.”