The expected rise in human heat-related mortality during summer season as a consequence of higher average temperatures, and more frequent, more intense and longer lasting extreme heat events is seen as one of the most important adverse health impacts under future climate warming scenarios. In the present poster we assessed temporal variations in the relationship between heat and cause- and sex-specific premature mortality in Spain by quantifying the relative excess of deaths attributable to heat and the relative contributions of moderate and extreme heat, considering changes in heat exposure levels during summer seasons from 1986 to 2015. We investigate whether hotter summers are increasing vulnerability through the increase in heat-attributable deaths or, on the contrary, there is no increase of such deaths, an therefore an adaptation response is taking place.