The thermal control concept of the Huygens probe must be designed for extremely hot and cold environmental conditions, which occur during the journey to Saturn's moon Titan. This task requires numerous analyses for the different mission phases. The paper presents the current thermal design of the probe and explains the thermal model structure as well as the different design cases which are taken into account in the analyses. Results of nominal calculations are presented for hot and cold cases and the Descent phase, which is the crucial mission period. The sensitivity of unit temperatures to different design parameters is plotted for the vacuum cases and a failure scenario is studied for the Descent phase.