Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center, hugs Christina Mathers, 43, a nurse from his team who became infected with COVID-19 at UMMC during the coronavirus outbreak, in Houston, Texas, on July 25, 2020. Mathers was told she tested positive for COVID-19 after she reported feeling ill during one of her shifts. "That's the hardest thing to ever hear ... It messes with you," said Mathers, who has been working every other day since April 29. "But I wouldn't go anywhere else but here." #

Dr. Joseph Varon (center) goes over the files of patients infected with COVID-19 at a daily meeting with his team of health-care workers, at UMMC, in Houston, on July 17, 2020. #

Lucy Dombovy, 37, a nurse, wears personal protective equipment as she signals to a colleague while peeking her head out of an intensive care unit for COVID-19 patients, at UMMC on July 10, 2020. #

Efrain Guevara, 63, who has been hospitalized after being diagnosed with COVID-19, lies on a hospital bed at UMMC, during the coronavirus outbreak in Houston, on July 17, 2020. #

Fernando Olvera, 26, a medical school student, helps Efrain Guevara, who has been hospitalized with COVID-19, get up from his hospital bed, at UMMC on July 17, 2020. #

The face shield of DeAnndrea Scott, a health-care worker, fogs up as she and a team of health-care workers perform CPR on a COVID-19 patient at UMMC on July 17, 2020. #

Fernando Olvera, 26, a medical student, wears a picture of himself around his neck for patients to know what he looks like, while wearing personal protective equipment, as he visits the room of a COVID-19 patient on July 25, 2020. #

Larissa Raudales, 18, who has been hospitalized with COVID-19, sits on a hospital bed as she is checked on by Fernando Olvera, a medical student, on July 25, 2020. "I was terrified ... I thought I couldn't breathe anymore," Raudales said. "I just thought I was going to practically die right there." #

Fernando Olvera, a health-care worker, places a sign reading "cleaned vent" onto a piece of medical equipment, as Dr. Joseph Varon and his team treat COVID-19 patients at UMMC on July 25, 2020. #

Dr. Joseph Varon, the chief medical officer at UMMC, wears personal protective equipment as he stretches his legs before treating COVID-19 patients on July 25, 2020. "Throughout my life, I have been in major disasters," Varon said. "Nothing has been as difficult to deal with [as] COVID." #