A primary study of the continuum emission from the arc of a high-intensity discharge (HID) lamp with an argon-mercury chemistry at pressures higher than 1 x 10(5) Pa is reported. Spectrally and spatially resolved calibrated continuum spectra from a vertically mounted test lamp (an MHN150 vessel filled at room temperature with 12 mg mercury and 400 mbar argon) are reported for the visible and infrared wavelength range 0.3-5.5 mu m. These spectra were analyzed to quantify the infrared (IR) losses and to determine the temperature profile inside the lamp. (c) 2004 Elsevier Ltd. All rights reserved.