JACKSONVILLE, Fla. — Debi de la Paz, a nurse at UF Health Jacksonville, worked in the intensive care unit during some of the darkest days of the Covid-19 pandemic last summer.

“It was bad,” she said of the first wave, “but now it seems to be even worse.”

UF Health Jacksonville is once again filling up with patients battling Covid-19. They are younger — many are in their 20s and 30s, some even in their teens — and they appear to be much sicker than those who flooded hospitals in the early months of the pandemic, de la Paz said.

Sabrina Oetterer, a nurse who started working at UF Health in March, said the change has been “insane.” These days, Oetterer said, it seems as though virtually every new patient coming into the hospital has Covid.

Florida, the third most populous state, has become the new national center for the virus, accounting for about a fifth of all new cases in the country. In hospitals across the state, doctors, nurses and staff members are confronting a fast-moving and escalating crisis with no end in sight.

Florida shattered Covid records over the weekend. On Saturday, the state recorded 21,683 new daily cases — the most since the start of the pandemic. On Sunday, the state broke a record for current hospitalizations with 10,207, the Florida Hospital Association confirmed. The previous record — 10,179 hospitalizations — was set July 23, 2020, more than a half-year before vaccinations started to become widespread.