43 heat-related deaths in one week in Catalonia

BarcelonaThe historic heat affecting the country this June has also had a direct impact on the population's health. Between June 1 and 30, the Mortality Monitoring System (MoMo) of the Carlos III Health Institute—the only tool that allows for a near-real-time snapshot of the deaths that occur daily in the country—estimates that 43 people died in Catalonia from causes attributable to rising temperatures. Specifically, the deaths occurred between June 22 and 30, coinciding with the highest temperature peaks. "We've never had a June with such sustained extreme temperatures: it's clear that we'll see a spike in mortality during this period, and we'll see what happens in July and August," warns Jacobo Mendioroz, Deputy Director General of Public Health Surveillance and Emergency Response at the Catalan government.

By comparing the average maximum and minimum temperatures in Catalonia with historical data, experts can determine whether the heat will have a direct impact on mortality, especially among frail people such as the elderly, children, or those with neurological problems. Alarm bells ring when the average of recent years is exceeded. In the last two years, for example, this threshold was exceeded on some summer days, and it was later found that the mortality curves were indeed steeper. However, in both 2024 and 2023, this temperature peak was reached in mid-July and the episodes lasted fewer than five days, while in 2025 it already occurred in June and was much longer than in previous years. For all these reasons, Mendioroz assures that it is expected that they will end up confirming an increase in mortality due to the heat.

According to MoMo data, which is reported directly by the regional governments, 22 of this month's Catalan victims were women and 21 were men. By age, all were over 65 (although there was one death in the 45-65 age range). Twenty-one of the cases were over 65, and thirteen were over 85. Mendioroz explains that people over 75 are more vulnerable to high temperatures and represent the majority of those who end up dying from heat, while heatstroke and heat exhaustion that end in death represent "a very low percentage," as they are "isolated cases," the expert maintains.

Jordi Mestres, a family doctor and member of the Catalan Society of Family and Community Medicine (CAMFiC), explains that there has also been an increase in people seeking emergency care due to general malaise, cardiovascular disease decompensation, dizziness, and fainting that may be related to the high temperatures of recent months. Despite this increase in patients, there are no healthcare data available, and Mestres believes that "it will be difficult to obtain real data," since the health system's records do not indicate whether the reason for the visit was high temperatures. "Sometimes we write down dizziness or loss of consciousness, we don't say it was heat, so it may be underestimated," warns the expert.

Differences by autonomous community

The 43 deaths reported between June 22 and 30 in Catalonia are identical to those reported by the Community of Madrid during this period, slightly exceeding the 34 in Galicia. By district, 19 have been reported in Barcelona, while 9 in Girona, 3 in Lleida, and 12 in Tarragona. In June of last year, however, no heat-related deaths were recorded in Catalonia. Mendioroz clarifies that, for now, these data are estimates and that a few more weeks are needed to fully analyze the data and determine how many people died during this June heat peak. "It is clear that as temperatures rise, so does excess mortality," he concludes.

MoMo is a nationwide system for reporting deaths to the different autonomous communities (Catalonia has an average delay of three days) that compares the expected number of deaths for each territory over a period of time with the most up-to-date death records. If the number of deaths that occur [observed deaths] exceeds the expected number [estimated deaths], this represents excess mortality or excess deaths. This system also differentiates which of these deaths correspond to changes in temperature, i.e., heat in summer and cold in winter.