- This research on thermal comfort is a complementary study from the previous one (Kitchai Jitkhajornwanich 2547). The methodology is based on field studies of thermal comfort towards adaptive theory. Herein the research becomes both quantitative by statistically analysing for comfort conditions, and qualitative by focusing on an explanation about the relationship between comfort, climate and culture. Areas of the surveys are on plateau and range of mountains in the western region in cold seasons. The results of the study find that there are 625 sets of data. The measurement of environmental parameters are reported in means values k air temperature at 28.0°C, globe temperature at 29.3°C, relative humidity at 59.8% and air velocity at 0.22 m/s. The personal parameters are too calculated in means values k activity rate at 1.13 met and clothing insulation at 0.33 clo. There are more than ninety percent of local people, responding their subjective thermal environments to be in comfort conditions. However there are a few wanting their environments to be cooler. From simple linear regression analysis, the comfort temperatures are found at between 28.2°C and 29.5°C, which are relatively high for cool seasons. The adaptive actions suggested by local people are in the same manner as the previous research. Finally, the research concludes with a proposal of a new comfort zone chart to be used as a substitute for the Bioclimatic Chart. By combining the data from this research and the previous (including all three seasons) the analysis establishes a comfort condition for hot and humid regions, interplaying of air temperature at 24.1°C - 32.9°C and relative humidity at 37.0% - 92.0%. This is a shifting up criteria from the Bioclimatic Chart, but it can effectively explain local thermal environments in a very logical way.