An essential support system of the Compact Ignition Tokamak (CIT) is the Vacuum Vessel Heating/Cooling (H/C) System. The requirement for the design of the dual function H/C System is to initially provide sufficient input heat energy to raise the temperature of the vacuum vessel from a 21°C ambient temperature to the operating temperature of 340±10°C and subsequently provide sufficient heat removal capacity to limit the cooling period between plasma pulses to 1 hour. The H/C System currently proposed for the CIT vacuum vessel accomplishes both of these system objectives using a single gaseous helium system flowing through a series of ducts attached to the exterior surface of the vacuum vessel shell. The design requirements, duct arrangements, and design analyses for the preliminary H/C System design are identified.