Document Type : Original Article


1 Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

2 Department of Occupational Health, School of Public Health, Qom University of Medical Sciences, Qom, Iran

3 Department of Physical Geography, School of Geography, University of Tehran, Tehran, Iran


Background: This study aimed to illustrate the applicability of the Humidex index for assessment of outdoor thermal environments in a wide range of weather conditions in different climates in Iran.
Study Design: This is a cross-sectional study.
Methods: Both  field measurements (1452 measurements) and the long-term meterological data (between 1965 and 2009) were used in this research. After determining the appropriateness of correlation coefficients between these two types of data,  only meteorological stations data were used to generalize the results to climatic regions. For this purpose, Arc/GIS 10.2 software was used.
Results: The results showed  three levels of comfort including safe, caution and stress regions by graphical maps. The results showed that the center and south of the country, especially at the middle and the end of the shift hours, experienced more thermal stress in summer months (ranging from 39.60±1.07 to 49.29±2.13ºC for central areas and ranging from 47.76±2.59to 57.71±1.65ºC for southern areas. In the northern regions, most of the measurements in different stations and time periods at spring were in caution condition and less than 1% of them experienced stress conditions.
The dependence of this index on the minimum metrological parameters (temperature and humidity), which are easily measured and reported daily in meteorological stations, and its non-dependence on the globe temperature, which is an unusual parameter in the measured metrological parameters, can be used as advantages of the humidex for assessment of the heat stress conditions in outdoor environments in different climates.


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