NOVELTY - The crew rest has an integral power source enabling the crew rest to operate independently of the power generation system of an aircraft. The power source is a fuel cell system. The outputs of the fuel cell system are supplied to the crew rest. The outputs include electrical energy, thermal energy, water, or oxygen-depleted air. The crew rest may also include a heat exchanger to cool water before or after the water is directed to appropriate areas or consumers. The electrical energy is used to power electrical outlets or a fire extinguishing system or to illuminate the crew rest.    USE - Crew rest, particularly a mobile crew rest, for offering crew members a resting place on long haul flights of aircraft.    ADVANTAGE - The crew rest is energy efficient and can be employed on any aircraft, including existing aircraft not specifically configured to receive the crew rest, since the crew rest does not require connection to a system port for receiving power from the aircraft's power generation system. Utilizing a fuel cell system to power the crew rest may reduce noise and carbon dioxide emissions. All by-products of the fuel cell system can be used to power the system itself, increasing system efficiency and improving the system's power-to-weight ratio. Need for data or communication with the aircraft can be achieved by wireless connection. Need for ventilation can be achieved by using a connection directly to the outside of the crew rest. Incoming air may be cleaned using a filter. By equipping the crew rest with a lavatory unit powered by the fuel cell system, aircraft crew can use a restroom separate from ones used by commercial passengers.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method of using a fuel cell system to power a crew rest associated with an aircraft such that the crew rest is configured to operate independently of an aircraft's power generation system.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic block diagram of a fuel cell system and various inputs and outputs relative to the fuel cell system.