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 United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., 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." REUTERS/Callaghan O'Hare TPX IMAGES OF THE DAY SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), goes over the files of patients infected with COVID-19, at a daily meeting with his team of healthcare workers, during the coronavirus disease (COVID-19) outbreak, at UMMC, in Houston, Texas, U.S., July 17, 2020. "I'm afraid that at some point in time I'm going have to make some very serious decisions," Varon said. "I'm starting to get the idea that I cannot save everybody." REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A death note written by Dr. Joseph Varon, the chief medical officer at United Memorial Medical Center (UMMC), about a COVID-19 patient who died while being intubated, is pictured at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), wears personal protective equipment (PPE) as he stretches his legs before treating COVID-19 patients at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 25, 2020. "Throughout my life, I have been in major disasters," Varon said. "Nothing has been as difficult to deal with (as) COVID." REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), and a team of healthcare workers perform CPR on a COVID-19 patient at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

An X-ray of a COVID-19 patient's lungs is looked over by Dr. Joseph Varon (not pictured), the chief medical officer at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), speaks to Henry Rodriguez, 39, who has been hospitalised with COVID-19, at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Riley Harrison, 67, who has been hospitalised with COVID-19, lies on a hospital bed as he watches television, at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 25, 2020. "I couldn't breathe," Harrison said. "If you got a death wish, play with COVID." REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Larissa Raudales, 18, who has been hospitalised with COVID-19, sits on a hospital bed as she is checked on by Fernando Olvera, 26, a medical student, at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., 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." REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

The body of a patient, who died during an intubation procedure, is prepared by Flor Trevino, 39, a nurse, to be transported to a morgue, at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A television showing the news is played inside a laboratory at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 25, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Fernando Olvera, 26, a medical school student, helps Efrain Guevara, 63, who has been hospitalised with COVID-19, get up from his hospital bed, at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare TPX IMAGES OF THE DAY SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Live camera footage of a patient hospitalised with COVID-19 is shown from a computer monitor during a daily meeting lead by Dr. Joseph Varon (not pictured), the chief medical officer at United Memorial Medical Center (UMMC), with a team of healthcare professionals, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Osvaldo Perez, 40, a medical school student, takes a break from treating COVID-19 patients, during the coronavirus disease (COVID-19) outbreak, at United Memorial Medical Center (UMMC), in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A medical school student takes a nap in the break room, as Dr. Joseph Varon, the chief medical officer at United Memorial Medical Center (UMMC), leads a team who are treating COVID-19 patients, during the coronavirus disease (COVID-19) outbreak, at UMMC, in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), sits at a table in the staff lounge as he talks on his phone, at United Memorial Medical Center, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), passes a piece of paper to Cesar Barrera, 24, a healthcare worker, as he checks on patients being treated for various diseases in the emergency room at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, the chief medical officer at United Memorial Medical Center (UMMC), fills out a COVID-19 patient's report as he leads a daily meeting with a team of healthcare workers, during the coronavirus disease (COVID-19) outbreak, at UMMC in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), puts on personal protective equipment (PPE), before treating COVID-19 patients at United Memorial Medical Center, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A man delivers balloons to a COVID-19 patient who was missing his daughter's birthday, at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

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 (PPE), as he visits the room of a COVID-19 patient, at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, July 25, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Lucy Dombovy, 37, a nurse, wears personal protective equipment (PPE) as she signals to a colleague while peeking her head out of an intensive care unit for COVID-19 patients, at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Hector Ortiz-Garcia, 63, who has been hospitalised with COVID-19, texts members of his family from his hospital bed at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 25, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), and a team of healthcare workers perform CPR on a COVID-19 patient at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

The face shield of DeAnndrea Scott, a healthcare worker, fogs up as she and a team of healthcare workers lead by Dr. Joseph Varon, the chief medical officer at United Memorial Medical Center (UMMC), perform CPR on a COVID-19 patient, at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), checks his phone after getting home from work, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 20, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), talks to Sarah, his wife, after arriving home from work, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 20, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A bobblehead of Dr. Joseph Varon, the chief medical officer at United Memorial Medical Center (UMMC), sits on his desk in his home office, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 20, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Sanathan Aiyadurai, 27, and Diego Montelongo, 27, who are medical students, review a COVID-19 patient's status during a daily meeting lead by Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, at UMMC in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Fernando Olvera, 26, a healthcare worker, places a sign reading 'cleaned vent' onto a piece of medical equipment, as Dr. Joseph Varon, the chief medical officer at United Memorial Medical Center (UMMC), and his team treat COVID-19 patients at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 25, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Dr. Joseph Varon, 58, the chief medical officer at United Memorial Medical Center (UMMC), wears personal protective equipment (PPE), as he checks on COVID-19 patients, at UMMC, during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 10, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Jonnie Harrison, 70, sleeps in a bed next to her husband Riley Harrison, 67, both of whom have been hospitalised with COVID-19, at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 25, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Efrain Guevara, 63, who has been hospitalised after being diagnosed with COVID-19, lies on a hospital bed at United Memorial Medical Center (UMMC), during the coronavirus disease (COVID-19) outbreak, in Houston, Texas, U.S., July 17, 2020. REUTERS/Callaghan O'Hare SEARCH "COVID-19 HOUSTON VARON" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.