A portable headlight assembly for illuminating a surgical site and moves with the surgeon, the headlight assembly having a headlight source, such as a HID lamp, to illuminate via a light cable coupled to receive and transmit the illumination in the range of natural daylight between 5000 and 6700 degrees Kelvin, a power supply that couples to the HID lamp when the light cable is located to receive focused light from it, and a control that monitors the operation of the headlight source and the portable power supply and is responsive to temperature of the portable power supply and radiation supplying illumination. The light cable extends between the HID lamp to guide illumination from the HID lamp and its reflector to a lens carried on a head strap worn by a practitioner for delivering the illumination to the surgical site.
