Development of a Heat Index Related to Air Quality and Meteorology for an Assessment of Work Performance in Thailand’s Urban Areas

A heat index is a key indicator directly related to meteorological factors influencing human health, particularly work performance. However, the interaction between air quality, meteorology, heat, and associated work performance is loosely defined, especially in urban areas. In this study, we develop a heat index (HI) related to air quality terms, including PM2.5, NOx, and CO, and meteorology terms, including temperature and relative humidity, to assess work performance in Thailand’s urban areas, including Chiang Mai, Bangkok, Nakhon Ratchasima, and Ubon Ratchathani, using a multivariate regression model. The regression models’ performance shows high R2 values ranging from 0.82 to 0.97, indicating a good level of performance. A recurring trend across all locations is elevated HI values during April and May, signifying typical pre-monsoon conditions in tropical regions. Following this peak, the values of the heat index (HI) begin to fall, possibly due to the start of the wet season. As shown by the decrease in productivity during periods of elevated heat index values, the observed increase in temperatures has noticeable effects on work performance.