This paper shows first results of mobile measurements, which carried out in summer 2009 to evaluate the thermal comfort for a „standardized‟ pedestrian in several urban areas of Leipzig. The analysis of the obtained data was conducted by calculating the mean radiant temperature as well as the Predicted Mean Vote (PMV). The results were compared to simulations applying the RayMan-program. Additionally to these findings to short-term stress, a study to the cumulated thermal stress was implemented into the analysis for the first time. Thereby, the thermal stress was considered which is perceived by a healthy ‟standardized‟ person during a one hour walk. As a first step a time rate of change of the PMV was defined for a measurement period. Using the example of the 20th August, 2009 in Leipzig, urban district Lößnig, a cumulated PMVaggregation of 0.7 was calculated and hence, a total (cumulated) PMV of 3.4 results in comparison to an arithmetically averaged PMV of only 2.7 for all measurement points along the route that were taken that day. Thus, a person perceives a severe thermal stress when walking the typical pedestrian route in Leipzig-Lößnig in one hour.