A pet bed adapted for use atop a floor mounted air register includes a bed structure and a base structure. The bed structure is an open-topped housing with a pet accessible entrance along a front side to facilitate a pet entering and lying within the bed structure. The base structure is a durable support extending downwardly from a floor surface of the bed structure. The pet bed is placed over the floor-mounted air register in order to allow a portion of air expelled from the air register to enter the open interior area of the bed structure through a plurality of ventilating apertures in the floor to provide temperature regulation to a pet within the bed while allowing the remaining flow of air to exit the pet bed through additional apertures along a front surface of the base structure in order to provide temperature regulation to the surrounding space.