Nearly all of the commonly used comfort predictors assume that the occupant is in a homogeneous environment, and are not fully effective in situations where this is not the case. In typical vehicle spaces, one commonly observes vertical temperature differences, radiant asymmetry, local air flows, and local body cooling. The purpose of this study is to describe a method for measuring non-uniform thermal environments using a new thermal manikin with controlled skin surface temperature. The manikin and its control logic are described, and an equivalent temperature based on the thermal manikin (teq) is proposed and discussed. To calibrate these methods, fundamental data were collected. For example, the clothed thermal manikin was tested in thermally non-uniform vehicle environments as created by solar radiation and HVAC system. The manikin-based equivalent temperature (teq) is shown to be effective at accounting for the effects of asymmetrical environmental conditions.