1. Introduction
Environment with the temperature above 32 C and relative humidity above 60% can be considered as hot and humid environment
[1]. With the rapid developments of economy and technology,
hot and humid environments are prevalent in workplaces,
such as steel mills, laundries, glass and ceramic units, deep mines,
aviations, metallurgy manufactures, rubber foundries, dye houses,
military facilities and some outdoor sport activities [2e4].