Daniel Devolder and Joan Ballester (Centre for Demographic Studies, Autonomous University of Barcelona, and Barcelona Institute for Global Health) explored mortality and temperature data from the Spanish National Institute of Statistics and the European Climate Assessment and Dataset project, respectively. The study, published in the prestigious journal The Lancet Planetary Health, is the first to comprehensively assess the impact of the 1°C increase in ambient temperature, observed in Spain since 1980, on mortality due to cardiovascular disease by sex and age.