The purpose of this study is to investigate the wage differentials between the heat exposure risk group and the no-heat exposure risk group. The heat exposure risk group refers to workers whose working condition leads them to sweat over 25% of the entire work hours without involvement of any physical activities. For analysis of wage differentials, the Korea Working Condition Survey data were used, utilizing Blinder-Oaxaca method and Juhn-Murphy-Pierce method. The analysis result showed that the no-heat exposure group was receiving higher wages. In most cases, this could be interpreted as the endowment effect of human capital. As the price effect that lowers the endowment effect, the compensating differential for the heat exposure group was found to be 1%. In the meantime, education level, work experience, and employment status were counteracting with the compensating differentials for heat exposure risks. The result of comparing the two data sets from 2014 and 2011 showed that the increasing wage gap between the two groups was not brought on by systematic factors of social discrimination. This study has its significance in that it suggests that factors of wage differentials among workers can be modified for thermal environment risks, which can result in the changes in working conditions as the impact of climate change amplifies.