Mike Schultz, a 43-year-old nurse from San Francisco, has shared photos of the devastation COVID-19, the disease caused by the new coronavirus, had on his body.

Schultz told BuzzFeedNews that he worked out regularly and had no underlying health conditions before he got sick.

In early March, Schultz and his boyfriend, 29-year-old DJ Josh Hebblethwaite attended the Winter Party Festival in Miami Beach, a circuit party that Hebblethwaite was working at. The annual party attracts thousands of people to the area for a week of events. At least 39 people who attended the Winter Party became ill and three men died.

The following week, while visiting his boyfriend in Boston, Schultz became sick with a high fever and had difficulty breathing. Hebblethwaite also became ill.

Schultz was hospitalized and had to be intubated for four and a half weeks.

Last week, Schultz shared on Instagram before and after photos of the dramatic toll the illness had taken on his body. The ordeal left Schultz, who lost 50 lbs, looking emaciated.

“I wanted to show everyone how badly being sedated for 6 weeks on a ventilator or intubated can be,” he captioned the photo. “Amongst other things, covid19 reduced my lung capacity with pneumonia. Over 8 weeks I've been away from family and friends. Getting stronger every day and working to increase my lung capacity. I'll get back to where I was in healthier ways this time … maybe even do cardio.”

Schultz said that he and Hebblethwaite received some negative criticism online for attending the Winter Party.

“The negative stuff bothers me,” he said. “But it doesn't bother me that much, because I've gotten so much positive feedback.”