A multilayered circuit board having a metal-free region vertically extending through at least a portion of a conductive layer, which lies generally parallel to a horizontal plane, vertically spaced from an outer surface. Heat-emitting and heat-sensitive components are mounted on the outer surface. The heat-emitting component is vertically and laterally spaced from the metal-free region, whereas the heat-sensitive component is vertically spaced and laterally aligned within the metal-free region such that the metal-free region is a thermal barrier that shields heat-sensitive component from radial heat flowing from the heat-emitting component.