Up to now, lots of thermal comfort models have been introduced to predict human being’s body thermal response to the changes in personal and environmental conditions. Among them, Gagge’s model because of its ability in estimating body physiological responses and thermal sensation in transient conditions has turned to one of the most used thermal comfort models. Although, this model uses transient mechanisms to determine body core and skin temperatures, but yet, simplified assumptions including steady heat and moisture transfer through clothing and disregarding thermal and mass inertia in the clothing is used in its structure. This study, by investigating various mechanisms of heat and moisture transfer in the clothing (steady heat and mass transfer, transient heat transfer-steady mass transfer, transient heat transfer-semi transient mass transfer) tries to compare upcoming results of these models with those of experiments. It was declared that considering transient heat transfer along with semi transient mass transfer in the clothing have positive effects on the results.