When an engineer considers reducing the stress on a man working in a heat stress environment, his typical response is to cool the environment. However, there are situations in which it is uneconomical to cool the environment, such as in furnace areas, steel mills, and deep mines, or in agricultural and individual factory operations, on construction jobs, even for military vehicles. An alternative for the designer is to ignore the environment and to cool the man--in other words, to cool the microenvironment rather than the macroenvironment.

Individual cooling falls into two general categories: conduction cooling and evaporative-convective cooling with a stream of air. Although considerable research on water and ice cooling has been done both at the Institute for Environmental Research and elsewhere. This paper deals only with air cooling.