Developing a new index for evaluating physiological safety in high temperature weather based on entropy-TOPSIS model - A case of sanitation workers.

Abstract Objectives Sanitation workers are at high-risk of suffering from heat-related illnesses in high temperature weather. However, some well-known heat stress indexes have limitations in practical application. This paper aims to establish a new index-comprehensive physiological index (CPI) for evaluating physiological safety. Methods Firstly, the real-time weights of physiological parameters are obtained by entropy method. Secondly, the new index- CPI is established based on the distance between the measured values and the ideal solutions by the technique for order of preference by similarity to ideal solution (TOPSIS). Then the reasonability of CPI is verified. Finally, the safety range of the CPI is determined. Results The mean skin temperature (MST), systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the sanitation workers are greatly affected by the high temperature. The weight range of the MST, tympanic temperature, SBP, DBP and heart rate is 0.155–0.274, 0.146–0.200, 0.173–0.399, 0.150–0.298 and 0.146–0.200, respectively. And the weights of MST, SBP and DBP account for a relatively large proportion, ranging from 60.1% to 70.9%. The danger range of the CPI is (0, 0.6] while the safety range of the CPI is (0.6, 1.0]. Conclusions The CPI can provide simple and easily-measured real-time monitoring of the physiological status. It has the potential to be a practical index for guaranteeing occupational health for sanitation workers in summer.