Hospitals across the United States are erecting triage tents outside emergency rooms, squeezing extra beds into break rooms and physical therapy gyms, and recommending delays in elective surgery to free up capacity as they brace for an anticipated surge in coronavirus patients.

No one can say if the preparations will be enough as the pandemic accelerates in the coming days and weeks. If the virus were to spread as rapidly in the United States as it has in China, Italy and Iran, hospital executives say the burden on the health-care system could be crippling, with demand for beds and some specialized equipment needed to treat patients and protect staff far exceeding supply.

With stories from Italy about hospitals turning away patients with severe respiratory symptoms, health-care executives say they are doing whatever they can to plug holes in a U.S. system that they acknowledge is not prepared to handle the very worst the pandemic could dish out.

“We are absolutely in a race,'' said Jenna Mandel-Ricci, vice president for regulatory and professional affairs at the Greater New York Hospital Association. The association’s members are coping with outbreaks in Westchester County and northern New Jersey, and working with state and local authorities in advance of the expected wave of infection throughout the New York City region. Some member hospitals are considering how they could surge to 20 percent above their licensed capacity, she said.

They hope that a combination of early planning and curtailing social interactions — with strategies like working from home and bans on large gatherings — will reduce the coming spike in viral infection and help stave off a widespread catastrophe. Throughout the country, medical teams are tallying hospital beds and intensive care units, laying emergency staffing plans, and taking stock of mechanical ventilators that keep critically ill patients alive and will be in short supply if there is a rapid growth in serious cases.

New York Gov. Andrew M. Cuomo (D) said Thursday that extreme measures were being considered, such as stopping elective surgeries, which should increase hospital capacity some 25 to 30 percent. In addition, he said, the state is calling up retired and former doctors and nurses and expediting their recertification. By Saturday, as the state announced its first coronavirus death, one of the city’s large hospital systems had taken that step. New York-Presbyterian said it would postpone all elective procedures and surgeries until further notice so that it could “concentrate on the adequacy of our equipment and supplies during this challenging period.”

MedStar Washington Hospital Center, the largest medical center in the D.C. area, this weekend is prepping its “ready room” — a giant, 2,500-square-foot, all-hazards-ready space built after the Sept. 11 attacks for mass casualty events — to use in the event of a surge of coronavirus patients.

Craig DeAtley, director of emergency management, said doctors are also making plans to expedite discharge for non-coronavirus patients whose care is winding down and who are safe to send home a day early and to convert several parts of the hospital into dedicated coronavirus areas. DeAtley said patients can do their part to help, too: “Of paramount importance is staying calm."

San Francisco is scrambling to locate temporary housing for those who have tested positive for coronavirus but do not need to be hospitalized. Health officials have temporarily leased recreational vehicles and are staging them in the Presidio, a national park and former military fort in the northern part of the city. Officials are also looking for other quarantine housing including unoccupied residential properties and vacant hotels, according to Grant Colfax, San Francisco’s director of health.

Hospital leaders, worried about keeping enough doctors and nurses on staff once medical personnel begin contracting the virus in greater numbers, said they were limiting face-to-face contact with their own staff members.

More hospitals across the country are taking swabs from noses and throats of patients in their cars, to keep them from coming into the emergency room.

In New Jersey, where two people have died and more than 70 people areconfirmed to be infected, plans were underway Friday to use an emergency medical mobile unit with seven beds at Hackensack University Medical Center to care for more patients. Another unit was being readied on the Jersey Shore.

Mass anxiety is causing problems at hospitals by driving unnecessary traffic to emergency rooms. Hackensack University Medical Center said it was managing the increase in hospitalizations but has been deluged with people with minimal or no symptoms seeking tests at the emergency room. It was diverting those “worried well'' people, up to seven visits an hour on Thursday night, into a separate biocontainment unit to be evaluated, instructed on how to reduce infections and sent home.

“They’re gumming up the system and gumming up acute care with the worried well,” said Joseph Underwood, chairman of emergency medicine at the hospital. “Responding to this type of rhetoric is creating a self-fulfilling prophecy.”

In Westchester County, the epicenter of New York’s outbreak, White Plains Hospital has received as many as 900 calls to a local hotline it set up. The hospital is just a few miles from New Rochelle, a community that is under a state-ordered lockdown to prevent the virus from spreading. “Only about 10 percent of patients who have coronavirus need to come to the hospital, and we want to educate these patients on whether they need to come here or not,” said Michael Palumbo, executive vice president and chief medical officer.

Planning for disasters like hurricanes and terrorist attacks is proving inadequate in a key respect for the coronavirus: moving patients out of the impact zone will have limited benefit in a fast-spreading pandemic that sickens thousands in multiple regions at once, say planners. In Manhattan, Lenox Hill Hospital’s medical director, Daniel Baker, said a nearby facility, the Manhattan Eye, Ear and Throat Hospital, which typically handles ambulatory patients, could be opened up for hospital stays for the critically ill.

A World Health Organization report on Wuhan, the epicenter of the outbreak, found 80 percent of the people infected had only mild symptoms, 15 percent needed highly concentrated oxygen and 5 percent — the most seriously ill — needed mechanical ventilators. Even more alarming, infectious disease experts have pointed out, is that the recovery period for many patients was three to six weeks.

The U.S. Department of Health and Human Services estimates a pandemic influenza, such as the one that hit the United States in 1957, would result in 38 million needing medical care, 1 million needing hospitalization and 200,000 needing to be in intensive care. In a severe scenario, such as in the 1918 influenza epidemic, the numbers would go up to 9.6 million hospitalizations and 2.9 million needing intensive care.

The United States, in comparison, has only about 924,107 hospital beds and 97,776 intensive care beds, according to a 2018 American Hospital Association survey.

Under relentless pressure from insurers and governments to cut costs, hospitals have adopted many just-in-time supply strategies and do not keep deep reserve supplies. They also seek to keep their rooms close to 100 percent occupied to maximize revenue.

“Everything is based on just-in-time inventories. We’ve depleted inventories in hospitals, and they don’t want their cash sitting on the shelves, they want it in the bank,'' said Brock Slabach, senior vice president of member services at the National Rural Health Association. “Supply chain management has become very efficient, but in times of stress, when you have beyond normal capacity surge, it creates problems.''

Hospital leaders are imploring the Trump administration to clear away red tape on an emergency basis and provide targeted funds to meet the demands of the expected explosion of patients.

Representatives of the nation’s academic medical centers and other hospitals want looser rules to allow nursing homes to accept patients who are less ill, freeing up hospital space for critically ill people infected with the virus. They also want waivers so doctors licensed in one state can treat patients in other states. And they want to lift a limit of 25 beds on “critical access hospitals” in rural areas.

New construction, additional staffing and lost revenue from canceled elective surgeries will place enormous financial strain on facilities requiring federal cash assistance, the Association of American Medical Colleges wrote to the coronavirus task force being led by Vice President Pence.

Chronic shortages of personal protection equipment plague health-care providers of all stripes but especially nursing homes, said Premier Inc., a national purchasing organization that procures drugs and supplies for hospitals and nursing homes. A nursing home in Kirkland, Wash., has been the source of 22 deaths alone.

But many nursing homes across the country can’t purchase N95 protective masks for their health workers because they have not bought them in the past, according to Premier. A system of `“allocation” in place among major distributors limits people to a historic purchase volume.

Premier has asked the Trump administration to draw down on the national emergency stockpile of masks and earmark millions of them for nursing homes, said Soumi Saha, senior director of advocacy at Premier. Premier sent out surveys to 28,000 nursing homes, which collectively have 2 million beds. More than half of those who responded said they have no access to personal protective equipment, she said.

Another dire shortage emerged at a hospital dealing with the pandemic in Washington State, Saha said. Evergreen Health ran out of a type of protective gear called a purified air-powered respirator, or PAPR, which is needed for workers to clean the room and handle the remains of a coronavirus patient who has died.

It took nine hours to locate 21 PAPRs, creating a delay in preparing for the next patient, Saha said. Airlines are prohibited from transporting PAPRs because they are categorized as a hazardous material, she explained, so it had to be transported by ground. Premier has asked the government to permit air transport of the devices.