We know this because he conducted a phone interview with Dan LeBatard while on his winter job.
Hartline: "Today I'm kinda busy. I'm working at a drive thru up in Ohio, freezing my butt off."
LeBatard: "You're working in a drive thru?"
Hartline: "Yeah, you know, a drive thru convenience store?"
LeBatard: "Yeah."
Hartline: "That's where I work."
$31 million contract? Pfft... Brian Hartline is a man of the people.