One of the biggest hazards of working on the set of a (fake) hospital is all the blood, according to Chicago Med star Colin Donnell. It's fake blood, of course, but no less messy than the real stuff.

"It gets really sticky, so we use a lot of Sterilube, which is just a fancy term for, like, K-Y Jelly. And so, that's all over," Donnell told during a recent tour of the Chicago Med set. "There's a lot of blood and lube."

Check out the video above to get a behind-the-scenes look at key areas of the hospital, including the operating room and what's known as the "football."

Chicago Med airs Tuesdays at 9/8c on NBC.