Abstract: An apparatus for treating neonatal jaundice is in the form of a garment (10, 40) which has semiconductor light sources (14, 214, 314) affixed thereto for radiating toward the "inside" of the garment when the infant is dressed in the garment. A portable energy source such as batteries (318) or a fuel cell (360) powers the array of light sources. A method according to the invention vests the infant in the garment, and energizes the light sources by coupling a battery to the light sources, or fueling and starting the fuel cell. The therapy is continued for as long as desired or needed.