People facing challenging socioeconomic conditions, older people, children, (pregnant) women, urban populations, outdoor workers, migrants, socially isolated individuals, and people with pre-existing conditions (particularly cardiovascular, respiratory, renal, and mental health conditions) are more vulnerable to heat. 

Numerous overlapping factors play a role here. Individual, social, and economic aspects influence heat-related health risks in a variety of ways. For instance, people living in poverty often reside in neighbourhoods with fewer green spaces and higher temperatures. Mortality during heatwaves is higher in districts with a low proportion of green space.

The newly published CCCA Fact Sheet entitled "Differences in Heat-Related Excess Mortality: Overview and Analyses for Austria" by Hanns Moshammer and Peter Wallner (Medical University of Vienna) provides information on how vulnerability to heat is distributed and varies according to different influencing factors.