Measurement and Evaluation for Productivity in Extreme Hot Environment

The productivity in extreme hot environment is not only influenced by the complexity of the task and the technical proficiency of the workers, but also closely related to the heat stress caused by the hot environment. In this study, three methods of productivity measurement were introduced, mainly referred to their applications and limitations. The method of using thermal sensation vote was based on the subjective feelings, and its application was convenient. The method of using wet-bulb globe temperature was based on the environment parameters and working time. It can be applied to a wide range of high temperature. While the method of using predicted mean vote had more comprehensive considerations of environment parameters and thermal sensation, but the complexity measurement of the environment parameters limited the usefulness of this method. Different from the three methods, this study proposed the physiological stress index to be the argument in the calculation of productivity. The physiological stress index combines both the environmental intensity and labor intensity. It reflects physiological conditions of the workers directly and has the potential to predict the productivity online.