IBP, Inc. (IBP) (defendant) was a producer of fresh meat products. IBP required its production workers to wear protective equipment when working on the production floor. IBP paid its production workers from the time the first piece of meat was cut to the time the last piece of meat was cut. Alvarez (plaintiff), a production worker, brought a class-action lawsuit against IBP, seeking to recover pay for the time spent donning and doffing protective gear and the time spent walking from the locker room to the production floor. The United States District Court for the Eastern District of Washington found that time to be compensable under the Fair Labor Standards Act (FLSA), 29 U.S.C. § 201, et seq. The court of appeals affirmed. The United States Supreme Court granted certiorari.