Background and Aim: In Occupational Health, the workplace environment is classified asone of the detrimental physical factors and based on the hygienic regulations, the individualand environmental monitoring of this factor and subsequently attempting to control it, isnecessary in workplace. Thus, this study aims to investigate how the bakers deal with the heatstress in traditional and modern bakeries of Kermanshah in December, 2016 andJanuary2017. Material and method: In this study, 116 bakers who were working in 63 bakeries werechosen randomly out of 213 traditional and modern bakeries of Kermanshah and the WBGTindex was measured in their waist. The preliminary assessment of the heat stressquestionnaire was utilized to evaluate the abstract effects caused by the heat for all of thebakers working in the bakeries of Kermanshah. Results: The results indicated that the mean of the WBGT indices in modern and traditionalpita bakeries were 25. 63± 2. 79 and 28. 55± 2. 82 respectively, which shows that the meanof the WBGT index in traditional bakeries was more than that of the modern ones(p<0. 05). Also, with regard to the abstract effects caused by working in bakeries, the results showedthat 64. 6%of the participants in both groups suffer from the muscular pain. Conclusion: This study showed that the heat stress index of the WBGT in traditionalbakeries in the winter was significantly more than the standard level; therefore, the baker'shealth in traditional bakeries of Kermanshah is alarming. This study indicated that most ofthe participants suffer from the muscular pain, so it is recommended that other researchersconduct more studies focusing on finding appropriate solutions in order to decrease themusculoskeletal effects of bakers.