The National Institutes of Occupational Safety & Health awarded a Phase I Small Business Innovative Research contract to Aspen Systems, Inc. The project will focus on the development and optimization of personal cooling through development and testing of an advanced thermal control method. Through the implementation of an optimal thermal feedback and control algorithm, the vapor-compression cooling (VCC) units performance can be improved for increased mission length, reduced power consumption, and reductions in size and weight. The use of an “intelligent” control algorithm which captures the physiological interaction of the user and cooling garment can lead to improvements in system operability and optimization of the amount of cooling provided to the user. Phase I technical objectives focus on proving feasibility of the most-promising control approaches. The current program offers the potential for commercialization of a robust vapor-compression personal cooling solution targeted for use by industrial workers without the logistics burden of existing products.