ORIGINAL PAPER Human biometeorological evaluation of heat-related mortality in Vienna Andreas Matzarakis & Stefan Muthers & Elisabeth Koch Received: 26 August 2010 / Accepted: 27 October 2010 / Published online: 20 November 2010 # Springer-Verlag 2010 Abstract The relationship between heat stress and mortal- ity in the federal state of Vienna (Austria) was analyzed from 1970 to 2007. Long-term trends of mortality data and short-term adaptation to heat stress were considered by two complex approaches. The evaluation is based on the human biometeorological parameter, physiologically equivalent temperature. The results revealed a significant impact of heat stress on the human health, with a significantly higher sensitivity on women compared to men. Additionally, higher risks of deaths due to cardiovascular and respiratory diseases were found. During the long period of 38 years, some significant decreases of the sensitivity were found, especially in the medium heat stress levels. This could indicate active processes of long-term adaptation to the increasing heat stress. 1 Introduction In summer of 2003, it was shown that there was a strong association between thermal stress and human health. Two heat waves occurred in June and August 2003 with the known effects of many thousands of deaths (Koppe et al. 2003; WHO 2003; Heudorf and Meyer 2005; Díaz et al. 2006; Robine et al. 2007), especially among older people (Díaz et al. 2002; Flynn et al. 2005; Laaidi et al. 2006; Barnett 2007; Hajat et al. 2007). The heat wave happened almost all over Western and Southern Europe. Although the effect of the heat waves in Austria was not found not to be extraordinary (Muthers et al. 2010a), still 130 additional deaths (Hutter et al. 2007) occurred during that time in Vienna. After the heat waves in summer 2003, many countries in Europe forced to initiate the development of heat health warning systems (HHWS) in order to early inform and protect their citizens. An HHWS consists of different components. In general, in a meteorological aspect it is responsible for the identification of heat wave events with serious health impacts. In the public health arena, it initiates and coordinates measurements to mitigate the most serious health outcomes due to the heat wave effect (WHO 2004). The identification of heat wave effect on human health requires deep knowledge of the relationship between heat load and mortality in the specific region as it differs among various countries (Keatinge et al. 2000; Gosling et al. 2007; Kovats and Shakoor 2008; Lin et al. 2010), but is connected to the mean climate conditions of a specific region (Iñiguez et al. 2010). Moreover, social factors such as the demographic structure of the population or the state of the health systems need to be taken into account. Hence, the development of an HHWS should firstly involve an analysis of the specific relationship for this region, which identifies useful parameters, thresholds and the intensity of the heat load impact. A brief description of HHWSs in Europe and the used meteorological factors or parameters is described in Koppe and Becker (2009). In most of the countries, a combination of daily air temperature (min, max, or mean) and sometimes air humidity were taken while a few countries used synoptic approaches, e. g., Italy. A more sophisticated approach based on the human energy balance and the derived perceived temperature (Jendritzky et al. 1979; Jendritzky 1990) is used in Germany. This approach also includes A. Matzarakis (*) : S. Muthers Meteorological Institute, Albert-Ludwigs-University of Freiburg, Freiburg, Germany e-mail: andreas.matzarakis@meteo.uni-freiburg.de E. Koch Central Institute for Meteorology and Geodynamics, Vienna, Austria Theor Appl Climatol (2011) 105:1–10 DOI 10.1007/s00704-010-0372-x