In this paper, workers thermal sensation is studied in workplaces affected by hot and cold thermal stress. Thus thermal environment data was collected to predict workers thermal sensation regarding EsConTer index. Moreover, through this index color scale real workers thermal sensation was gathered. The clothing insulation was also valorized for this study regarding clo calculation. The results showed, unequivocally, that thermal sensation, clothing insolation and workers metabolism are directly and greatly influenced by thermal environment.