A Record-Breaking Summer for Mortality
According to data from the Daily Mortality Monitoring System (MoMo), published by the Carlos III Health Institute (Instituto de Salud Carlos III, ISCIII) under the Spanish Ministry of Health, a total of 5,234 excess deaths related to high temperatures were recorded nationwide from May 16 to August 31 this year. This figure sets a new summer record since the system began operating in 2015.
On a monthly basis, the death toll showed an increasing trend. Approximately 937 related deaths were recorded in June, surging to 2,025 in July. August (up to the 31st) reached 2,149 cases, making it the third-deadliest month on record, surpassed only by the peak of 2,217 deaths in July 2022.
The Science Behind “Excess Mortality”
It’s important to clarify that not all of these 5,234 deaths were directly caused by heatstroke. The MoMo system provides an estimate of “excess mortality.” This model combines daily registered deaths, temperature data, and historical mortality patterns to calculate the number of deaths “beyond what would be expected” under specific high-temperature conditions.
Epidemiologists point out that cases directly attributable to heat shock (heatstroke) account for only a very small fraction of total heat-related deaths, around 2% to 3%. The vast majority of deaths occur because high temperatures exacerbate pre-existing health conditions, such as cardiovascular disease, respiratory illness, or kidney dysfunction, ultimately leading to a fatal worsening of their condition.
The Elderly: The Most Vulnerable Victims
Age has been the most critical risk factor in this heat crisis. The data shows that out of the 5,234 deceased, a staggering 5,068 were individuals aged 65 and over. Among them, 3,268 deaths occurred in the 85-and-over age group, accounting for approximately 63% of the total, highlighting the extreme vulnerability of this demographic. In terms of gender distribution, women were more affected, with 3,143 female deaths (about 60% of the total) compared to 2,091 male deaths.
Extreme Weather Normalization and Public Health Response
Preliminary data from Spain’s State Meteorological Agency (AEMET) indicates that the average temperature this summer was about 2.5°C higher than the 1991-2020 reference period, surpassing last year’s record of 2.2°C higher. AEMET also noted that the five hottest years on record (from January to August) have all occurred in the last five years, indicating that extreme heat is becoming increasingly frequent.
Experts from the Spanish Society of Epidemiology warn that heatwaves have shifted from being an occasional weather event to a severe and persistent public health problem. They not only pose a direct threat to the elderly and individuals with chronic illnesses but also place immense pressure on the entire healthcare system. Looking at Europe as a whole, the situation is equally grim, with an estimated 35,000 premature deaths continent-wide this summer due to the heat. Experts are calling for nations to move beyond individual-level heat protection measures and establish more robust public health warning systems, social support networks, and take action on a macro level—including in urban planning and climate change adaptation—to mitigate the risks of future extreme weather events.
