Dr. Sana Maheshwari, an emergency room doctor in New York City, is sick with COVID-19.

She had been seeing patients with coronavirus -related symptoms since late February, but in the last two weeks, the number of cases coming into her hospital surged.

Around the same time, Maheshwaris hospital started running low on personal protective equipment (PPE), as did hospitals all around the country . So Maheshwari did what all American medical workers were asked to do last week by the Centers for Disease Control and Prevention.

She began reusing her mask instead of throwing it away after each use like she was taught to do in medical school.

Honestly, it felt dirty. It felt gross, Maheshwari told HuffPost. At the end of the day, youre taking off all the stuff that you were wearing for 12 hours, and you walk out of the hospital feeling really gross.