The suit alleges that county officials acted with negligence by allowing 51-year-old Frank Polk to get locked in a visiting room for 32 hours and willfully and wantonly deprived him of food, water and a toilet.
"He could hear voices of guards on the other side of the door," Polk's attorney Cannon Lambert told CBS Chicago. "Presumably, if he could hear them, they could hear him."
Polk said he feared for his life, thinking he may never get out of the Kafkaesque nightmare.
"You're not going to see your grandkids and faces and people you love," Polk fretted.
"And [I] didn't get a chance to say goodbye."
Cook County Jail director Cara Smith told the Chicago Tribune that the lawsuit is not a surprise and "does not change our reaction to this unfortunate incident."
"We remain very sorry for what Mr. Polk went through and focused on making sure it does not happen again."