For a circuit board populated with numerous components having different heights, the need for numerous individual heatsinks to accommodate the circuit board's multilevel surface is eliminated. Instead, heat is transferred to a single integral heatsink via a thermal-conductive material (i.e., a thermal phase change material and/or a resilient gap filling material). A fastener secures the thermal-conductive material between the bottom portion of the heatsink and the multilevel surface, and compresses the thermal-conductive material therein, creating a thermal path sufficient to transfer heat from the multilevel surface to the heatsink so that the circuit board operates within specified design parameters.