The first time I heard the cheering, I didn’t realize what was happening. I was walking in the middle of a Manhattan city block at precisely 7 p.m. An eerily quiet streetscape, muted by the pandemic, erupted into noise. Pots and pans crashed, and people leaned out of their windows and cheered. I asked a nurse walking beside me what was going on. “It’s for us,” she said. “I think they’re cheering for us.”

In a month of endless work, solitude and death, this one moment for me, an emergency room physician, stands out as oddly emotional and strangely serene. It was a way for people to thank us, the doctors and nurses and other health-care workers, to let us know that the risks we were taking in fighting the coronavirus pandemic were valued.

That was April. The cheering has stopped. But that does not mean the risk to us has abated. Far from it. The shutdowns have eased, and yet in much of the country the numbers have surged, and more of us are dying. Outside New York, covid-19 is killing more Americans, and on the front lines, it’s killing more health-care workers. The Kaiser Foundation is keeping track. In a project with the Guardian, Kaiser is publishing obituaries of health-care workers who have died of covid-19. They’re up to 782, a startlingly high figure that most likely underestimates a terrible reality. The Centers for Disease Control and Prevention, working with incomplete data, counts nearly 98,000 covid-19 cases among health-care workers, with 517 deaths. One study found that health-care workers had a 12 times greater risk of testing positive for covid-19 than people in the general population, with an even higher risk for those without adequate personal protective equipment (PPE).

It’s clear that the fight against the virus is not going well. Cases are rising in 40 of 50 states, with exponential growth in Arizona, Florida and Texas. New York’s worst day was April 15, when 11,571 people tested positive. By comparison, Florida logged more than 15,300 new cases on Sunday, the most by any state in a single day. That’s a greater number of cases in a similar-sized population, with one key difference: New York’s peak occurred 23 days after instituting the shutdown measures that the governor of Florida still steadfastly refuses to implement.

My colleagues in Texas are now facing the risks that we in New York faced in April. Hospitals are still wary of shortages in PPE, choosing to sanitize and reuse masks that are designed to be disposable. Perhaps even more troubling are the physical implications of a covid-19 surge. One colleague described how his Texas hospital’s emergency department is boarding covid-19 patients in hallways because it has simply run out of room. Some of these patients receive high-flow oxygen or aerosol-generating treatments that can spread the virus liberally, further risking the staff members taking care of them. Working in these conditions is arduous, and burnout is common. Every piece of PPE has to be removed correctly to avoid contamination and changed between patients. One small error can mean inhaling millions of copies of the virus.

The situation in Arizona is even more dire. On June 29, Arizona became the first state to formally institute crisis standards of care — a phrase that sounds benign but translates to medical rationing. It’s the first time any state has done this. Effectively, the state is giving hospitals the latitude to deny resources to some in order to save others. Importantly, this doesn’t apply only to covid-19 patients; it applies to everyone. If you have a heart attack or get hit by a car, you’re in the same queue as every other patient competing for scarce resources. And “resources” doesn’t mean just ventilators, it means people — health-care workers. Splitting a ventilator is difficult (no two people breathe in exactly the same way — try it). Creating more skilled workers quickly is impossible. The risks involved make crisis-care decisions even more difficult. Do I choose to intubate a patient and save her life, but possibly sacrifice my own? Does it matter if she’s elderly or infirm and might die anyway?

In New York in April, many of us believed that crisis standards were right around the corner. Fortunately, we avoided having to make some of the most heart-wrenching decisions because New York state locked down and aggressively contained the virus. This is not the case in Arizona, where the governor still hasn’t taken some of the measures that we know are effective. Arizona bars that were previously reopened were not ordered closed again until June 30, and the governor still refuses to mandate masks statewide.

Masks and social distancing have been debated since the earliest days of the outbreak. If you’re waiting for evidence that these measures work, you needn’t wait any longer. In June, a group writing for the Lancet pooled all the available data on masks and social distancing in the setting of coronavirus infection. The results were striking. The rates of infection were almost five times higher for patients who had not worn masks. Social distancing was also very effective and, not surprising, more distance resulted in less infection.

That is why we health-care workers need you to wear a mask. It’s clear that not all governments have kept pace with covid-19. It’s clear that we all have some role to play in stopping this pandemic. Health-care workers continue to die fighting for all of our lives. We all have to assume some responsibility for slowing the spread of this disease. You don’t have to clap. But wear a mask. My life and the lives of my colleagues across the country depend on it.