Abstract: A breathing apparatus for use by mountain climbers and others operating in low temperature atmospheres utilizes body heat and perspiration to warm and humidify the air from the atmosphere as it is inspired by the user. A hose-like element is positioned adjacent to the body and inside the clothing. The element is of a porous construction to permit passage of air and equipped with auxiliary holes for the same purpose. An inlet valve connects to the outer atmosphere and a filter and a connector lead to a face mask positioned against the nose and mouth of the user. An outlet check valve completes the apparatus.