A heated breathing circuit with radiant barrier is provided. The breathing circuit includes an airflow conduit configured to receive gas at input end and configured to deliver said gas to a patient at an output end, a heating element disposed inside the airflow conduit configured to heat the gas inside the airflow conduit between the input end and the output end and a heat shield disposed between the heating element and an outside surface of the airflow conduit such that the heat shield prevents heat energy loss from within said airflow conduit.
