(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.)

(THE CONVERSATION) The Conversation is running a series of dispatches from clinicians and researchers operating on the front lines of the coronavirus pandemic. You can find all of the stories here.

"Doctora," a community health worker yelled from across the room. "People are lined up along the fence. Under the sun. Do we have water for them?"

I was standing in the middle of an air-conditioned room in April at a COVID-19 testing site for Latino farmworkers and their families in the...