A man cools off in Cordoba on June 10, 2022. EFE

Last year's hottest summer on record caused 12,000 deaths in Spain, new study finds

Extreme temperatures caused 50% more deaths than previous years, similar to levels during the extreme summer of 2003

Álvaro Soto

Madrid

Monday, 1 May 2023, 12:04

A new study has brought into question the true number of people who died from the heat in Spain last summer.

A total of 12,054 people died from heat-related deaths according to a study published in the journal Epidemiology, which used different criteria to that of the MoMo Report, by the Carlos III Institute, which recorded 4,774 deaths last year.

The 12,000 figure was 50% more deaths than in previous years and a number only comparable to the exceptional summer of 2003.

Researchers from the Foundation for Climate Research, the Spanish National Research Council (CSIC), the University of Valencia and the Spanish Consortium for Research in Epidemiology and Public Health (Ciberesp) calculated that of the 12,054 people who died last summer, 6,738 were caused by moderately high temperatures and 5,316 by extreme temperatures.

The differentiation between deaths caused by moderate and extreme heat was one of the major differences between the two reports.

The new report recorded an average of 26.5C as the threshold - which was exceeded for five days in June and two weeks in both July and August, more days than in any other year.

Number of deaths increased very significantly

On those key dates of extreme heat when temperatures soared, so did the health risk, with more than 5,000 people dying, well above the 863 who died in 2021 or 554 in 2019.

“We experienced more days of extreme temperatures than in previous summers and it was during these periods that the number of deaths increased very significantly," head of data at the Foundation for Climate Research (FIC) Dominic Royé said.

Royé also said that models such as MoMo were "outdated" and "have underestimated" the number of heat-related deaths.

Increase in deaths among patients with previous respiratory and cardiovascular pathologies

According to the study, extreme temperatures lead to an increase in deaths among patients with previous respiratory and cardiovascular pathologies. Deaths "that do not usually occur in hospitals because the patients are not admitted," Royé said.

"Deaths due to heat stroke represent a very small percentage, 2 or 3%, of deaths due to high temperatures. The rest have more to do with previous pathologies that cause, for example, heart attacks," he said.

The study also noted that temperature increases of just one degree could greatly increase the number of deaths.

For this reason, it is important to make the population aware that maximum temperatures of 39, 40 or 41 degrees are not the same thing," Royé said.

Last summer was the hottest in Spain since 1961, when historical records were first collected.

Temperatures were 2.7 degrees above the historical average, and that is set to be tested again this summer as the country is already grappling with unseasonably warm temperatures in April and May.