A field study of thermal comfort was conducted in hot-humid vernacular environments of Thailand during hot and rainy seasons in 2003. There were 1,322 subjects in the surveys. All subjects were free to wear any clothes, do any activities, and adapt to secure their comfort, according to their norm of daily living. The result from analysis found that there was a good relationship between comfort and climate, although the thermal conditions in the study were relatively extreme. A new comfort zone can be established, comparing with the classic Olgyay’s (1963) comfort zone. Hence this can propose to shift comfort zone to a new dimension for thermal comfort study, especially in the contexts of contemporary tropical architecture and vernacular environments