Most people know immunologist Anthony Fauci as the doctor at the forefront of the White House's response to the coronavirus pandemic — the grey-haired, bespectacled man who stands alongside President Donald Trump at pandemic press conferences.

The job has reportedly earned him a personal security detail due to threats of violence. He takes it seriously, but also in stride.

"[T]his is the life I've chosen," Fauci told CBS's Gayle King. "It's my job."

And what a job it is: Over Fauci's 36-year career as an infectious disease expert, he has handled outbreaks and pandemics including HIV, SARS, MERS and Ebola.

Now, at 79, Fauci is working 19- to 20-hour days thanks to the COVID-19 pandemic.

It's Fauci's wife of 35 years, Christine Grady, a nurse bioethicist, who is there at the end of those very long days to remind him to take care of himself too.

"I try to get him to rest, to drink water, to eat well, to sleep, and to be selective about what he agrees to and say no to some things," Grady tells CNBC Make It.

Typically, Fauci, who has served as the director of the National Institute of Allergy and Infectious Diseases since 1984 under six different administrations, is known for his 16-hour work days and his habit (as a former marathoner) of squeezing in a seven-mile run at lunchtime.

However, in recent weeks his hours have gotten longer and his runs have become short power walks.

Grady, 67, who works at the National Institutes of Health Clinical Center, says she and her husband are doing their best to ensure their own health while both juggling demanding jobs.

While Grady and Fauci don't socially distance from each other while at home near North Bethesda, Maryland, "we are trying to get some sleep and eat as regularly as possible, washing our hands all the time and cleaning surfaces and anything we touch, especially when coming in from outside," Grady says.

Of course Fauci is still working, and so is Grady. As a bioethicist, Grady is tasked with figuring out the "right" thing to do when conflicting values and uncertainty arise in clinical care, research and health policy. She says there are "many challenging issues to deal with" right now.

And since Grady works at a hospital, she physically distances herself from her coworkers while at the office.

"Almost all of our meetings are virtual," she says, and when it's necessary to meet in person, she makes sure to "stand or sit at least six feet apart" from other people. "And we are washing our hands all the time and wearing masks."

Even though Grady's and Fauci's schedules have left them little time together in recent weeks, they try to do what they can.

"We like to power walk, and have succeeded in walking a few times together," she says. "Other times I walk without him."

Grady says she's "coping like everyone else" during this challenging time.

As for advice about staying safe during the pandemic, Grady echoes her husband: "Take care of yourselves, use protective gear appropriate to your job, remember to always wash your hands and avoid close contact with people," she says.

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