In order to operate a motor vehicle, a position sensor and a radiation source as well as at least one vital sensor having a detector are provided. The position sensor delivers a measurement signal having information regarding a predetermined area of the vehicle interior of the motor vehicle. The radiation source emits a predetermined radiation after activation. The vital sensor detects a reflected portion of the radiation that is emitted by the radiation source. The measurement signal of the vital sensor is representative of at least one vital parameter of a given vehicle occupant. As a function of the measurement signal of the position sensor, a position is determined of at least one predetermined reference body part of the vehicle occupant in question. The orientation of the radiation source is controlled as a function of the detected position of the predetermined reference body part of the vehicle occupant in question.
