An electrically-powered device intended to be used for the uniform heating of the contents of a microplate, test tube, and/or assay/reagent/test card, as part of an incubation step required during the in vitro diagnostic processing of a clinical specimen. It typically consists of a heat-conducting panel/unit on which the microplate/tube/card is placed, and an electronically-controlled heating element for precise temperature control. It may also be referred to as a heater and may be used as a stand-alone device or a modular component as part of a system.