In addition to vehicle aerodynamics, optimization of interior climate control systems is also an important CFD application. Applications include interior heating and cooling (including solar radiation) and windshield defogging and defrosting. SC/Tetra is capable of handling very complicated geometries with its sophisticated and robust grid generator and low memory consumption solver. In addition, SC/Tetra offers unique capabilities for predicting occupant comfort by employing a fully coupled human body thermoregulatory model. This model considers the detailed human body vascular system and individual physiological factors.