A few of these messages of support remain on the wall of the empty unit — a card with a child’s sweet drawing of a heart, a family photograph, a colorful thank-you poster from a local Girl Scout troop. On my way out of the empty unit, I snap a photo of the posters on the wall.

Still, even as I say “so long” to nurses returning to their own units, I am sadly aware that this is not an ending. The numbers of the sick and dying in my city decreased because we were practicing social distancing. And now, cases in areas of the country that reopened more rapidly are rising, with patients in respiratory failure filling intensive care unit beds in Arizona and Texas.

I see photos of the doctors and nurses there gearing up in their P.P.E., and I feel only exhaustion and dread, knowing what comes next — isolated deaths, terrible FaceTime goodbyes. I had believed that the hard-won knowledge of those of us in hard-hit places like New York City and Boston would begin to spread as efficiently as the virus, but now I am not so hopeful.

Just a few nights ago, at home in my own bed, I was awakened by a page alerting me to a patient in the E.R. She was Covid-19-positive, a recent diagnosis.

It continues.

So we keep the closed unit empty and waiting. Though the hospital is filling once again with heart attack and cancer patients and those who are awaiting transplants, we don’t move any of them into these Covid-19 beds. Not yet. We maintain a backup schedule of critical care doctors who will return to work in the event of another surge.

These empty beds remind us that the virus is still here, and if we do not stay far from one another and wear our masks and wash our hands, if we do not continue to sacrifice our desires and do these uncomfortable things, the beds will inevitably fill again. And if they do, we will be more prepared. My state has ramped up testing and a robust system of contact tracing. Here in the hospital, we are more familiar with the nuances of this disease and its management.

But everyone is tired. The adrenaline of those early days has turned to profound fatigue.

And, of course, there are still people to care for, many of whom have been intubated for weeks. On my recent night shift, I’m relieved to learn that one of our patients, a young and previously healthy gardener who was intubated and comatose the last time I saw him, is finally waking up after nearly 60 days.