Solar heat radiation can impose significant heat stress on employees performing outdoor tasks. A prototype infrared reflecting vest was developed to offer protection to agricultural workers and constructions workers who are exposed to high levels of outdoor solar radiation. The prototype vest was tested using a laboratory based thermal manikin exposed to controlled heat radiation intensity levels. The tests showed that a vest including 3.2 cm spacers was able to reduce heat gain by 30% without imposing a significant corresponding insulation heat gain. The thermal cross-over point for such a vest was lowest in comparison to others configurations tested. Commercial development of such a vest for use by agricultural workers and construction workers in desert environments is encouraged.