A breathing circuit (100) comprising: an airflow conduit (110) configured to receive gas at input end and configured to deliver the gas to a patient at an output end a heating element (129) disposed inside the airflow conduit configured to heat the gas, at least partially by emitting infrared radiation to be absorbed by water vapor inside the airflow conduit to maintain a predetermined temperature inside the airflow conduit to prevent condensation of the gas between the input end and the output end and a heat shield (200) disposed on an interior surface (118) of the airflow conduit such that the heat shield prevents energy loss from within the airflow conduit. The heat shield comprises an infrared shield configured to prevent absorption of the infrared radiation by the airflow conduit.
