 -- One boss proved why it's important for employees to take sick days, after he helped save the life of his sales manager by telling him to go see a doctor.

Mike Bell of McKinney, Texas, underwent open-heart surgery and treatment after a blood infection stemming from an infected tooth led him to tear his aorta as he coughed, putting him in critical condition.

The day in April when he went to the hospital and ended up in critical condition, Bell, 58, woke up feeling fine. But his car dealership boss, Gus Rodriguez, didn't think Bell looked healthy enough to stay on the sales floor.

"I didn't really feel that bad, I felt a little dizzy," Bell, who has since fully recovered and is back at work, recalled of the day he went to the hospital.

"My boss, the second he came up to me said, 'Mike, you look like [expletive,] you need to go to the doctor and figure out what's going on.'"

Just hours later, when Bell was in the hospital, he collapsed on his way to an X-ray and was rushed into emergency surgery.

Doctors found that Bell had a tear in his aorta, a critical blood vessel coming out of the heart, and the tear was causing his lungs to fill with blood.

"Without prompt intervention he would have died within a few hours," Dr. Mark Pool, cardiac surgeon with the Texas Health Physicians Group, told ABC affiliate WFAA in Dallas-Fort Worth.

Bell said he underwent emergency open-heart surgery with doctors giving him just a 30 percent chance of pulling through. He said throughout the ordeal Rodriguez was there with the Bell family as they awaited the results.

"The last thing I remember is being scooted on a conveyor belt" for an X-ray, Bell told ABC News. "The next thing on Saturday morning is Dr. Pool standing over me."

ABC News was not able to immediately reach Gus Rodriguez for comment.

Bell said the doctors' best guess for why the aorta tore is that a blood infection from an infected tooth and subsequent coughing led to the tear that put him in critical care. After 14 days in the hospital, Bell remained at home for months as he recovered.

He said his boss remained a source of support and help, by making sure Bell didn't fall behind financially and even making sure he didn't come back to work until he was fully healthy again.

"He took care of me and made sure I could still pay the bills," Bell said, who is coming forward now to raise awareness about the importance of sick leave. "He didn't let me come back until I gained some weight."