An apparatus has a first member having an exposed peripheral surface and an electrically and thermally conductive portion. A circumferential array of magnets of alternating polarity are mounted for rotation about an axis relative to the first member inboard of the peripheral surface, the magnets being in sufficient proximity to the electrically and thermally conductive portions so that the rotation of the magnets about the axis is effective to generate eddy currents, in turn, is effective to heat the electrically and thermally conductive portion and, thereby, heat the exposed peripheral surface.