Subtitles section Play video Print subtitles concern is also growing for doctors and nurses working tirelessly to help covert 19 patients and contracting the virus themselves at an alarming rate. 140 employees at one hospital alone to Brigham and Women than Boston. Testing positive Matt Gutman has much more on that story this morning. Good morning, Matt. A good morning, Michael. Given their daily exposure, I suppose it's not surprising that health care workers are getting sick. But here's what's disturbing. Experts are now telling us that the viruses are like poison, and the higher the dose, the more fatal it can be. And so higher doses combined with poor protective gear, making for a dangerous combination. Frontline health workers themselves are turning into patients at alarming rates. It's being called an epidemic within an epidemic. 20% of Cove it positive patients in Ohio and Minnesota, our health care workers in Boston, over 700 health care workers testing positive they are exposed to the virus more than anyone else. Every day when I go to work, I feel like a sheep going to slaughter. My colleagues and I are writing our last will and testament, experts say. It's not just the frequency of exposure, but also that health care workers are exposed toe larger doses of the virus as well. When you get exposed to a virus, you're a mere system immediately starts mounting a response at the same time the virus starts spreading within the body. An outcome depends on which wins the race viral spread or the immune response. When you start with a high dose of virus, it gives it a head start on the res, meaning the virus can overload the immune system of even the healthy people like Frank Garbin. And by then his breathing was almost non existent. And when they're paramedics, your life they tried to revive on for about 45 minutes. Garbin wasn't just any covert patient. The 60 year old was an E R doctor, the first in the nation to die from Cove it his best friend, Deborah Lyons, on the phone when he passed. He also knew exactly when he got it. He knew it was those four shifts that he had to use the same mask he knew it. Shortages in protective gear, triggering protests in California and Kansas City. Nate is a nurse in New Orleans. What are the biggest shortages you're seeing on the day today. I think we're short gowns, obviously. The disposable isolation gowns, uh, the and 95 mask. We're using Mass for 5 to 7 ships, generally reusing the same masks over and over. Masks are stored in those brown paper bags on those racks, but even when they do have proper protective gear, medical professionals can fall ill. I did everything right, and I still came up positive, so I'm not really sure what's going on there yet. Still, doctors and nurses air turning up every day. And despite all of that danger, volunteers are now turning out in droves in California, New York, Colorado, over 120,000 retirees or people in other areas of medicine have volunteered, despite all of that danger to join the fight against Covert 19. Michael. Yeah, all heroes on the front line. Hi, everyone, George Stephanopoulos here. Thanks for checking out the ABC News YouTube channel. If you'd like to get more video show highlights and watch live event coverage, click on the right over here to subscribe to our channel. And don't forget to download the ABC News after breaking news alerts.