CNN  — 

While the world collectively shelters in place to protect against coronavirus, medical professionals flock to the front lines to work long hours tending to a burgeoning number of infected people.

One of them is Dr. Nicola Sgarbi, 35, who unknowingly became part of a growing photo trend of health workers coping with this exponential rise in sick patients.

Italy has been indicative of the spike in infections. On Saturday, the country had more than 47,000 coronavirus cases and some 4,000 deaths from the disease. Sgarbi is a doctor in training who works in the ICU of the civil hospital of Baggiovara in Modena, Italy.

Almost everything about Sgarbi’s shift on March 13 was part of his new normal since the outbreak: working 12 hours to treat Covid-19 patients while wearing protective equipment. But at about 8 p.m. that day, he stripped off his face mask and snapped a quick selfie, something he rarely does.

Dr. Nicola Sgarbi is one of countless medical professionals around world putting in extra hours to help people suffering from coronavirus.

“I mainly took the photo for two reasons. Firstly, to send it to my partner, to tell her that I had finished my shift at work and that I was on my way home, slightly bruised,” Sgarbi told CNN over email. “Secondly, to show it to my 1-year-old daughter when she will have grown up. I will be telling her about this moment.”

Sgarbi’s photo was posted on Facebook and Reddit, where it was shared more than 74,000 times and voted on at least 118,000 times, respectively. The photo drew worldwide praise and comparisons to “Batman and Superman rolled into one,” among other things.

Since then, numerous photos and stories of health workers in and out of protective gear have been posted around the internet. Each one captures the physical and emotional toll this pandemic is taking.

Sherry Dong, 25, is a registered nurse who has worked in the medical ICU at Johns Hopkins Hospital in Baltimore for more than two years. On Friday, she shared a photo on Reddit taken during a hectic day at work. The photo shot to the top of Reddit’s front page and collected more than 2,100 comments.

“My heart is grateful and my mind is heavy seeing medical professionals all over the world putting themselves at risk battling against this outbreak. I think the medical community has found various ways of coping through social media outlets,” Dong told CNN in a Reddit message.

Protective equipment has become a fixture at many US hospitals.

“Our uniformed readers should make sure they do not contribute to the growing problem of supply shortages (ie: N95 masks, face masks, disinfectants, gloves, etc.) and consider donating to local hospitals,” she said.

Some of the most striking photos have come out of Wuhan, China, the epicenter of Covid-19.

A portrait was taken on February 17 of the marks left on the face of nurse Cao Shan after working in the isolation ward in Wuhan’s Jinyintan Hospital, designated for coronavirus patients.

“She and her husband, a doctor also working at the hospital, have slept in the vehicle for 23 nights to avoid bringing viral hazards around, save commuting time, and give their assigned nearby hotel room to colleagues,” the photo caption read.

The marks of a mask are seen on the face of nurse Cao Shan after working in the isolation ward in Jinyintan Hospital, designated for Covid-19 patients, in Wuhan, China.

These photos are an important oral tradition that will hopefully provide a cautionary tale to the general public, said Dr. Anna Yaffee, director of the Global Health in Emergency Medicine Section at Emory University. Yaffee hopes these images are a powerful reminder of the realities health care professionals face on the front lines every day.