A sleeper cab is a semi-truck with a living compartment built directly behind the driver's seat. It allows long-haul drivers to take their required hours-of-service rest breaks without renting hotel rooms. These cabs range from small, basic bunk spaces to large custom compartments with beds, TVs, refrigerators, microwaves, and auxiliary climate control units.
Sleeper cabs run on long-distance routes where drivers are away from home for weeks at a time. The sleeping area must meet federal safety rules, including size minimums, ventilation, and emergency exits. To keep the cab comfortable without idling the main engine all night, many trucks use auxiliary power units (APUs) that generate electricity and run the air conditioner.