Wearable air conditioners

They are developing a heat-actuated lightweight and compact cooling unit capable of keeping down temperatures within protective suits for several hours. Chilled water circulates through a vest, and is capable of providing relief up to 6 hr. The chilled-water loop is itself cooled by a heat exchanger in an absorption-cycle cooling system. Here, a thermochemical compressor -- powered by thermal energy from the burning of a fuel such as propane -- circulates refrigerant through the heat exchanger. Such heat-actuated compressors consume much less power than their electromechanical counterparts, making them well suited for portable refrigeration applications.