ORLANDO—Nurse Darlene Andrews stood before a small crew responsible for stopping the latest pandemic surge from overrunning seven of AdventHealth’s Orlando-area hospitals.

She quickly listed occupancy at each hospital. Six were beyond full capacity, with one at 123% for adults. Nearby wall-mounted screens streaming hospital data showed more than 90 patients—some with Covid-19, some seeking other care—needed beds. One had been waiting more than two days.

A hospital in Altamonte Springs, Fla., and another east of downtown Orlando were the current hot spots, nurse Andrew Stakelum told the group, a team that oversees work that has become critical for U.S. hospitals during each pandemic surge: finding an open bed for severely ill patients. Delays leave patients unstable from Covid-19 or other ailments in dangerous limbo.

Prior surges have helped the team and other staff of AdventHealth’s mission control, which monitors hospital capacity and coordinates transfers, prepare for the latest wave of patients, executives involved in the response said.

The flagship hospital, north of downtown Orlando, took all Covid-19 patients in the spring 2020 surge. That wasn’t possible in the larger surge that followed in July 2020, when mission control staff triaged and moved patients across all seven hospitals.

Now, the highly contagious Delta variant is amplifying the number of Covid-19 patients and the speed at which they arrive, the executives said, making beds everywhere essential.

Staff in AdventHealth’s mission control praying at the start of their shift.

An ambulance crew after a patient transfer at AdventHealth’s flagship hospital in Orlando.

Darlene Andrews, center, and staff at AdventHealth’s mission control last week.

“This surge has come at us like a freight train,” said Neil Finkler, AdventHealth Central Florida’s chief clinical officer. It is happening as demand for other medical care has rebounded, he said.

Florida’s steep rise in coronavirus cases since late June has pushed Covid-19 hospitalizations to new records. Coronavirus patients now fill at least 43% of Florida’s adult intensive-care beds.

Finding hospital beds as demand soars is a complex logistical challenge on a tight clock, say medical and disaster experts. The sickest patients need specialized equipment and staff in a matter of hours or less. “That’s where time counts, where minutes look like hours,” said Tabarak Qureshi, the intensive-care medical director at AdventHealth’s Altamonte Springs hospital.

The race to stay ahead of the flood of patients at AdventHealth’s hospitals is orchestrated in an office tower next to its flagship hospital.

Dozens of screens along the walls stream updates on open beds, patient moves and the queue of waiting patients. Red on the screens alert the staff where hospitals need urgent relief. Exclamation points dot screens where patients who need beds are crowding emergency rooms.

Emergency rooms everywhere have been hit harder in this surge, unlike in the past, when Covid-19 cases were more clustered, said Penny Porteous, mission control’s executive director. “This one is starting at our front door,” she said.

July was the busiest month this year for the 14 AdventHealth emergency rooms around Orlando. Seven aren’t attached to hospitals, increasing the need for transfers, Ms. Porteous said. Transfers across AdventHealth’s Orlando-area operations hit a pandemic record last month.

Near-instant data streamed from hospital records is critical for mission control, AdventHealth executives said.

Lack of timely hospital data has undermined the pandemic response. The pandemic exposed fragmented and cumbersome systems for moving essential data between hospitals and public-health officials, hampered by technological snags, competitive concerns and lack of investment.

A patient being transferred into a room at AdventHealth Orlando.

Rising hospitalizations across a region force hospitals to refuse transfers they would normally accept. AdventHealth’s Orlando-area hospitals denied 58 transfers in July for lack of an available bed, less than the pandemic peak of 97 in January. As of this month, the hospitals started to decline and to wait-list transfers from overcrowded hospitals for patients who don’t require specialized services found at AdventHealth, Ms. Porteous said.

Overwhelmed hospitals and lengthy delays in care put patients at higher risk of death, said Jeffrey Dichter, a disaster-planning expert at the University of Minnesota. “They’re not getting the care they need,” he said.

As the Delta variant sweeps the globe, scientists are learning more about why new versions of the coronavirus spread faster, and what this could mean for vaccine efforts. The spike protein, which gives the virus its unmistakable shape, may hold the key. Illustration: Nick Collingwood/WSJ The Wall Street Journal Interactive Edition

Research on Covid-19 patients across more than 550 hospitals between March and August 2020 found patients’ risk of death doubled at hospitals hardest hit by surges, said the study’s lead author, Sameer Kadri, head of clinical epidemiology in critical care for the National Institutes of Health’s clinical research hospital. Results were published last month in the Annals of Internal Medicine.

Eduardo Oliveira, executive medical director for critical-care services for AdventHealth Central Florida, said its hospitals have maintained staffing critical to avoiding harm to patients.

A flight crew in Orlando preparing to pick up a patient for transfer from a nearby county.

A nursing station at AdventHealth’s flagship hospital in Orlando.

Dr. Eduardo Oliveira in his Orlando office.

One day last week, Mr. Stakelum and other mission control staff ended a morning huddle with prayer. The slammed hospital in east Orlando was the priority.

That abruptly changed. Altamonte Springs hospital’s 40-bed intensive-care unit didn’t have enough beds for patients who suddenly needed them, Dr. Qureshi had alerted Dr. Oliveira. Four patients elsewhere in the hospital were rapidly getting worse. Dr. Oliveria contacted mission control.

Data showed one option, Dr. Oliveira said: the flagship hospital. Within a few hours, mission control had transferred three Altamonte Springs patients there.

As mission control raced to move the patients, AdventHealth executives in Orlando met to address an urgent need for more beds, said Kay-Lyn Yohman, executive director for clinical outcomes for AdventHealth Orlando. More beds meant finding more skilled nurses, she said.

Days earlier, AdventHealth Central Florida had halted all nonessential surgery to redeploy dozens of workers from operating rooms to help overrun units elsewhere in the hospital.

On a surgical floor one day last week, a small crew handled three procedures that couldn’t wait. Typically, as many as 60 people staff the floor’s eight operating rooms for neurology patients, including children who need surgery for seizures, said Darin Santangelo, surgical services executive director for AdventHealth Orlando.

Redeployed staff helped free nurses for the most complex tasks, but it still wasn’t the staffing needed to add 20 ICU beds to the flagship hospital overnight, Ms. Yohman said. To do that, they decided intensive-care nurses would each need to care for one additional patient.

“ ‘This really is a lesson to all of us and a warning for other parts of the U.S. that have not yet experienced this.’ ”

— Vincent Hsu, AdventHealth’s executive director of infection prevention

The hospital opened the extra 20 beds later that evening. The next morning, most were full. “Twenty is really only a plan for 24 hours,” Ms. Yohman said.

The latest surge likely won’t peak in coming days, based on modeling, said Vincent Hsu, AdventHealth’s executive director of infection prevention. The worst could have been avoided with more widespread vaccination, he said.

“This really is a lesson to all of us and a warning for other parts of the U.S. that have not yet experienced this,” he said.

Vaccines are effective at preventing severe illness and hospitalization, he said, urging people to get shots. That includes AdventHealth staff, who can’t work when infected. “Every person is extremely valuable for us,” Dr. Hsu said.

AdventHealth doesn’t mandate its workforce get vaccinated. A spokesman declined to comment further.

Harley Yap left the flagship hospital Thursday after arriving the day before struggling to breathe. Mr. Yap, 68, and his wife had been diagnosed with Covid-19 the week before.

His wife, who is vaccinated, was fine, he said. He didn’t get the vaccine because he typically doesn’t take medication, he said, and his family is long-lived. He said he has now changed his mind.

AdventHealth Central Florida halted all nonessential surgery to redeploy dozens of workers from operating rooms.

Write to Melanie Evans at Melanie.Evans@wsj.com