(CNN) -- Talk about dedication to the job.
Detroit paramedic Joseph Hardman is being hailed as a hero for performing CPR on a patient having a heart attack -- even as he began to have one himself.
One doctor said the odds of this happening are "one in a million."
"A sudden explosion-type feeling in my chest" is how Hardman, 47, described the incident to CNN affiliate WXYZ.
Hardman's partner drove him and the patient to the local hospital.
Both men had identical stents put in to remove blockages, and both are recovering.
Hardman knows how lucky he was to already be on his way to an ER, telling reporters "If I hadn't been in the position I was in, I would have been deceased."
"I would have to say one in a million is about appropriate" a hospital doctor told WXYZ. "I haven't ever seen it and I haven't heard of it".
Hardman has been working as a paramedic in Detroit for 15 years, and says he has no prior medical history of heart problems.
The blockage was found in a key artery that is often referred to by cardiologists as the "widow maker".
Doctors say he likely faces months of rehab before he'll be able to return to work.