A patient circuit heating system for a pressure support system (50, 80) having a patient circuit, comprising: a heating apparatus structured to be operatively associated with the patient circuit; and a controller operatively coupled to the heating apparatus, the controller being adapted to control a temperature of the patient circuit by: determining one or more environmental parameters relating to environmental conditions around the pressure support system (50, 80); determining one or more gas stream parameters relating to a gas stream output by the pressure support system (50, 80) to the patient circuit before the gas stream is provided to and heated by the heating apparatus, wherein the one or more gas stream parameters include a temperature of the gas stream output by the pressure support system (50,80) to the patient circuit before the gas stream is provided and heated by the heating apparatus; determining a desired temperature for the patient circuit based on at least the one or more environmental parameters and and the one or more gas stream parameters; and controlling operation of the heating apparatus based on the desired temperature characterized in that the one or more environmental parameters include an ambient humidity around the pressure support system (50, 80). a heating apparatus structured to be operatively associated with the patient circuit; and a controller operatively coupled to the heating apparatus, the controller being adapted to control a temperature of the patient circuit by: determining one or more environmental parameters relating to environmental conditions around the pressure support system (50, 80); determining one or more gas stream parameters relating to a gas stream output by the pressure support system (50, 80) to the patient circuit before the gas stream is provided to and heated by the heating apparatus, wherein the one or more gas stream parameters include a temperature of the gas stream output by the pressure support system (50,80) to the patient circuit before the gas stream is provided and heated by the heating apparatus; determining a desired temperature for the patient circuit based on at least the one or more environmental parameters and and the one or more gas stream parameters; and controlling operation of the heating apparatus based on the desired temperature characterized in that the one or more environmental parameters include an ambient humidity around the pressure support system (50, 80). determining one or more environmental parameters relating to environmental conditions around the pressure support system (50, 80); determining one or more gas stream parameters relating to a gas stream output by the pressure support system (50, 80) to the patient circuit before the gas stream is provided to and heated by the heating apparatus, wherein the one or more gas stream parameters include a temperature of the gas stream output by the pressure support system (50,80) to the patient circuit before the gas stream is provided and heated by the heating apparatus; determining a desired temperature for the patient circuit based on at least the one or more environmental parameters and and the one or more gas stream parameters; and controlling operation of the heating apparatus based on the desired temperature characterized in that the one or more environmental parameters include an ambient humidity around the pressure support system (50, 80).