A header assembly for a power distribution assembly in which the power distribution assembly includes a mounting portion and a plurality of current carrying components. The header assembly includes a first header segment made from a first material and a second header segment disposed on the first header segment and being made from a second different material. The first header segment and the second header segment together form a composite header assembly structured to be mechanically coupled to the mounting portion and electrically connected to at least some of the current carrying components. At least one of the first material and the second material is thermally conductive and electrically insulative.