Donald Trump's pick for Labor Secretary, Andrew Puzder, is the chief executive officer of CKE Restaurants, the parent company of fast food chains Hardee's and Carl's Jr. — and his record there is a cause for concern among working people.

While CEO, he's been accused of tolerating the exploitation of labor, with nearly 60 percent of Department of Labor investigations of CKE locations showing at least one violation of federal wage laws. Puzder has also advocated for the immediate repealing of the Affordable Care Act, and is a harsh critic of minimum wage increases and paid sick leave.

As head of the Department of Labor, Puzder would oversee laws related to all of these issues, prompting speculation he will ignore or overturn new rules on overtime and workplace safety passed by the outgoing Obama administration.

After being denied permission to invite former CKE employees to speak at Puzder's upcoming confirmation hearing, Sen. Elizabeth Warren (D-Mass.) held her own special hearing on Tuesday to give them a forum to talk about life under Puzder. And what they shared paints an ugly picture.

Laura McDonald, a 24-year Carl's Jr. employee and former manager who left in 2012, spoke of working 60 hour weeks with no overtime, receiving just 47.5 hours of pay. Her store was chronically understaffed, forced to depend on part-time employees routinely given less hours than promised.

McDonald said CKE's benefits were also too expensive, ensuring most employees went uninsured. While she received sick time and paid vacation, she was rarely allowed to use it, saying the constant need to be on the clock ultimately resulted in the end of her marriage.

McDonald told Warren and other Democratic senators she couldn't think of anyone less qualified to protect employee rights.

Another worker, Lupe Guzman, spoke through tears about how she worked at Carl's Jr. for seven years and was still only making $8.75 per hour. She worked 50 hours a week, often traveling around restaurants in the area, and couldn't set a schedule to pick up her children from school. Ultimately, she was demoted after asking to be placed at one store close to her apartment.

At one point, she simply had wages stolen, with 30 minute "breaks" deducted from her checks, despite her not being allowed to take breaks on her overnight shift. Guzman said wage theft was common and took multiple forms. The personnel computer would freeze, for example, forcing hours to be put in manually, but her managers had to be constantly reminded to do so. Often, the money simply was never paid. Her safety was also put in jeopardy, as she was robbed at gunpoint twice, with no support from corporate afterwards.

Roberto Ramirez, an 18-year Carl's Jr. employee, told his story through an interpreter. He spoke of doing the work of four people, saying he was so overworked he had to start 30 minutes before clocking in. He too was a victim of wage theft, with a paycheck stolen and cashed by a manager.

When Ramirez complained, he was told by his district manager that the restaurant wasn't responsible for his boss's theft. In retaliation, he claims his hours were reduced, and that he ultimately had to quit. He worried that if Puzder is confirmed, what happened to him will happen to other workers, and not just at Carl's Jr.

In sum, the workers painted a picture of a company that under Puzer's watch prioritized profits over workers and wages, which isn't an ideal background for a cabinet official who is supposed to protect the rights of labor.