The observation of the attendance of open-air terraces in restaurants, taverns and cafés provides an indirect way to estimate human reactions on thermal conditions. This paper reports the use of this human biometeorological survey method in two taverns located in Szeged (Hungary) in order to investigate the correlation between the relative attendance of outdoor places and the actual thermal conditions. The latter was quantified by the most popular human comfort index, Predicted Mean Vote (PMV), calculated by the bioclimate model RayMan from measured meteorological parameters influencing the thermal comfort sensation. In a 6 week long period, the relative attendance of the beer gardens of two taverns offering different microclimatic environments was observed in the afternoon hours (between 12 and 3 p.m.). The results proved that the attendance of outdoor places increases up to a specified PMV value, then decreases due to the intensified heat stress. This tendency is not only in harmony with the common human attitude, but also confirms the correctness of the applied bioclimate index (PMV)
