According to the MACE Heat Attributable Mortality in Spain statistical model, heat was a factor in the deaths of 48 people in the Balearics between January 1 and June 21. These were deaths when, with the exception of some days this month, heat was moderate; the highest temperature in June has been 39.2C.
A team of scientists at the University of Valencia developed the MACE model and website. They draw on official data from the MOMO Daily Mortality Monitoring System and from temperatures recorded by the AEMET met agency. For 2024, the model attributed 236 deaths to heat; the hottest months of 2025 are yet to come.
One of the scientists, Dominic Royé warns that there will be an increasing number of deaths attributable to high temperatures. "According to a recent study we conducted, Palma is expected to experience an extreme heat event every six years when temperatures rise by 1.5C. If they reach 2C, attributable mortality would be 9%, compared to 4% in 2000."
Based on their research, the most deaths attributed to heat were 339 in 2022. The 236 in 2024 were therefore comparatively low; in 2023 there had been 277. Royé points out that, although summer 2024 wasn't as hot as some other recent summers, temperatures were still above normal in much of the Balearics.
Officially, only heat stroke is recognised as cause of death from heat. The vast majority of deaths caused by high temperatures are not certified as such because it is practically impossible for a doctor to certify them. The MOMO system estimates the number of deaths caused by high temperatures, but this is based on excess mortality.
"With MACE, we apply a state-of-the-art statistical model widely used in environmental health studies." Factors such as pre-existing medical conditions, homes without air conditioning, prolonged exposure to high temperatures, and others are considered. Royé stresses the importance of considering heat-related deaths. "Adaptation to rising temperatures has played a crucial role in preventing mortality in Spain, but it remains insufficient, especially considering that one in four heat-related deaths can be attributed to the aging of the population."
Professor of Public Health and Preventive Medicine, Joan Carles March, explains that there are various causes of heat-related deaths - severe dehydration, kidney failure, brain damage due to high temperatures, cardiac arrest due to heat overload, and thrombosis. "The alarm goes off when body temperature exceeds 40°C. From that moment on, various physiological processes in the body are altered. Inflammation occurs, accompanied by an enzyme surge that interferes with the regular functioning of vital organs. Once initiated, it is difficult to reverse. The first symptoms are headache, confusion, and light-headedness, and these escalate to loss of consciousness, seizures, and heart failure."
He says that the people most vulnerable to heat-related death are the elderly, especially those who live alone or have chronic illnesses; outdoor workers; infants and young children; people with heart, kidney, or respiratory conditions; those without access to shade, water, or adequate ventilation, e.g. the homeless and people in substandard housing; and those taking medications such as diuretics.
March refers to risks for outdoor workers, and in this regard the CCOO union says it will report the AENA airports authority to the government's labour inspectorate for having changed criteria for the high-temperature protocol that applies to outdoor ground crew at Palma Airport. Enrique Spera, head of the union's occupational health unit, says that the protocol used to be triggered when the temperature 35C. "This year, for reasons unknown, they have increased the temperature to 39°C. Therefore, they have not considered it necessary to apply the high temperature protocol until that temperature is reached."
He was referring to the temperature on Wednesday, when the south of Mallorca was on amber alert for high temperatures from noon to 7pm. As it turned out, according to AEMET, the maximum temperature at the airport was 38.2C, below the 39C amber alert threshold but clearly well above the previous 35C.
In Palma, the EMAYA municipal services agency has a series of guidelines for high temperatures, such as stopping to cool off for ten minutes every hour. However, workers believe this isn't enough. They aren't even offered water - they have to bring it from home - and there are vehicles with defective air-conditioning systems.
The two main unions in the Balearics - the CCOO and the UGT - have made heat stress an issue in the negotiations for the new hospitality industry collective bargaining agreement. The unions have been calling for more rest periods for workers who are exposed to high temperatures, e.g. waiters/waitresses and kitchen staff.
The maximum temperature in Mallorca on Wednesday was 38.9C in Pollensa.