There is a brutal constancy to the workweeks of these two women: 72-hour weeks piled one atop another.

In Corona, Queens, Celina Alvarez chops chayote and avocados and chickens in a dank restaurant basement. And a few blocks away, Rocio Loyola makes juice drinks.

Now and then Ms. Loyola, 35, wears down and the chill of flu runs through her body, and she vomits in the employees’ bathroom. And, she says, her boss shakes his head and warns:

You go home, you’re fired.

As for Ms. Alvarez, 48, some months ago her heart throbbed, her arms and chest heavy with ache. On her single day off she walked into a clinic, and a doctor listened through his stethoscope and told her: Your heart is in bad shape.

He checked her into the hospital. A few days later, she was discharged and walked 15 blocks to beg her employer for her job back. She said he was disgusted: You’re old and you’re sick. With that, she said, he sent her back to chop in a basement filled with two inches of gray water.