This online application calculates daily mortality due to heat in Spain, using methodology is based on the March 2023 paper Heat-attributable Mortality in the Summer of 2022 in Spain The application uses the daily mortality data for Spain from the All-cause Daily Mortality Monitoring System (MoMo) and the average summer temperature (June, July and August) in Spain calculated from the reference stations defined by the Spanish State Meteorological Agency (AEMET).