Effects of Cold AIr on the AIr Passages and Lungs

The absence of reliable information concerning the effects of cold air on the air passages and the lungs and concerning the rate at which inhaled cold air is warmed within the body led to the undertaking of this investigation on dogs. In order to observe the pathologic and physiologic changes resulting from the inhalation of cold air independent of any indirect or secondary effects that might result from the simultaneous chilling of the surface of the body, the air was brought into the mouth and throat through a vacuum-jacketed (Dewar) cannula, and the animals were not otherwise exposed to cold. Care was exercised to see that the dogs had no source of air for respiration other than that which had passed through a cooling system. The air was chilled by passage through a radiator (converted automobile heater) which was immersed in a large Dewar container filled with a mixture of