Airway Heat and Water Vapor Transport

Effectiveness of the conditioning process is dependent upon respiratory tract geometry, ambient air temperature nd humidity (Cjj (,), inspira- 

2 Role of Airway Heat and Water Vapor Exchange in Disease and Injury 

The importance of respiratory heat and water losses is not confined to the respiratory structures. Inspiration of cold, hot, or dry air poses the potential threats of thermal injury or desiccation to the airway epithelium - T8,69 g challenge to whole-body thermoregulation. 

Under certain conditions, such as hyperbaria,airway heat losses can account for a considerable percentage of total body heat production (in some cases 100%). Normally these threats are ameliorated by rapid moderation of inspired air temperature and humidity by exchanging heat and water vapor between the mucus and airstream in the upper airway. Recovering much of the heat and water vapor contained in expired air minimizes heat and water losses to the ambient environment and aids in whole-body thermoregulation. 

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