Hospitals have put their pandemic plans into action, adding more beds and creating makeshift COVID-19 wards. But in the hardest-hit areas, there are simply not enough doctors, nurses, and other specialists to staff those beds. Some health-care workers told me that COVID-19 patients are the sickest people they’ve ever cared for: They require twice as much attention as a typical intensive-care unit patient, for three times the normal length of stay. “It was doable over the summer, but now it’s just too much,” says Whitney Neville, a nurse based in Iowa. “Last Monday we had 25 patients waiting in the emergency department. They had been admitted but there was no one to take care of them.” I asked her how much slack the system has left. “There is none,” she said.

The entire state of Iowa is now out of staffed beds, Eli Perencevich, an infectious-disease doctor at the University of Iowa, told me. Worse is coming. Iowa is accumulating more than 3,600 confirmed cases every day; relative to its population, that’s more than twice the rate Arizona experienced during its summer peak, “when their system was near collapse,” Perencevich said. With only lax policies in place, those cases will continue to rise. Hospitalizations lag behind cases by about two weeks; by Thanksgiving, today’s soaring cases will be overwhelming hospitals that already cannot cope. “The wave hasn’t even crashed down on us yet,” Perencevich said. “It keeps rising and rising, and we’re all running on fear. The health-care system in Iowa is going to collapse, no question.”

In the imminent future, patients will start to die because there simply aren’t enough people to care for them. Doctors and nurses will burn out. The most precious resource the U.S. health-care system has in the struggle against COVID-19 isn’t some miracle drug. It’s the expertise of its health-care workers—and they are exhausted.