In this paper a thermodynamic analysis of human heat and mass transfer based on the 2nd law of thermodynamics in presented. For modelling purposes the two-node human thermal model was used. This model was improved in order to establish the exergy consumption within the human body as a consequence of heat and mass transfer and/or conversion. It is shown that the human body's exergy consumption in relation to selected human parameters exhibit a minimal value at certain combinations of environmental parameters. The expected thermal sensation, determined by the PMV* value, shows that there is a correlation between exergy consumption and thermal sensation. Thus, our analysis represents an improvement in human thermal modelling and gives even more information about the environmental impact on expected human thermal sensation.