The assessment of the thermal bioclimate is based on the human energy balance and derived indices such as Physiologically Equivalent Temperature (PET) or Universal Thermal Climate index (UTCI). These two indices were compared over a period of ten year based on hourly data in a middle European city with a temperate climate. The analysis performed shows that the differences obtained result from the different thermophysiological settings of clothing insulation. For conditions with extremely high vapour pressure values, UTCI yields higher values than PET, which could describe the thermophysiological stress more appropriately
