High temperatures are rarely accompanied by anything good. They can cause extreme weather events, such as an increase in hurricanes due to warmer waters, increased droughts, and a worsening of forest fires. However, There is a significant relationship between high temperatures and mortality rates, which requires urgent attention, especially in a world facing climate change. For more information on the impacts of these phenomena, you can consult the article on the impacts of heat waves.
There is a risk for everyone. Activities or work carried out outdoors are particularly dangerous during heat waves. A tragic example is the case of a 54-year-old man who, two weeks ago, lost his life due to a heat wave while working on asphalt in Morón de la Frontera. However, there is a group of people who, regardless of their work, are more susceptible to the effects of high temperatures.
Who and how does it affect?
On a physical level, high temperatures particularly affect older adults, as well as those with cardiovascular or respiratory conditions, or diabetes. It has been proven that not only is exposure to high temperatures fatal, but also the length of time they persist and are prolonged. Data shows that on a day with high temperatures, the percentage of deaths increases by 4% compared to the estimated average.If these temperatures persist for two days, deaths increase to 10% the following day, and to 22% on the third day. The risk is even higher in children under one year of age, where deaths rise to 25%, and doubles if they also suffer from respiratory, digestive, or cardiovascular conditions.
On a psychological level, there are also devastating effects, with studies finding a link between suicide rates and heat waves. Analyzing historical records, we have the Great European Heat Wave of 2003, which resulted in an estimated 35,000 additional deaths. To explore these effects further, you can read about how the climate change raises temperatures.
It is essential to remember the importance of protecting yourself from the heat when temperatures rise. Stay hydrated and avoid physical activity during the hottest hours. It's crucial, especially for the most vulnerable groups, but also for the general population. The effects on our bodies are proportionally harmful as temperatures rise.
Recent data on heat-related mortality
According to recent studies, more than 47,000 people died in Europe as a result of high temperatures in 2023, which is considered the warmest year on record globally, and the second warmest in Europe. This information was published in Nature Medicine by a team led by the Barcelona Institute for Global Health (ISGlobal). They estimate that, without the adaptation processes that societies have developed over time, the burden of heat-related mortality last year would have been 80% higher.
The study used temperature and mortality records from 823 regions in 35 European countries over the period 2015 to 2019 to employ epidemiological models to estimate heat-related mortality in 2023. Although the summer of 2022 was characterized by persistent extreme temperatures, in 2023 no major thermal anomalies were recorded, but two episodes of high temperatures In July and August, they were responsible for more than 57% of the estimated global mortality, with more than 27,000 deaths. For a more in-depth analysis of climate change and its impact, you can read about heat waves.
Southern European countries are the most affected
The analysis yielded a total of 47,690 deaths estimated in 2023 in the 35 countries, of which 47,312 occurred in the hottest period of the year, from May 29 to October 1. When looking at population, the most affected countries in terms of heat-related mortality rates are in the South of Europe, specifically Greece (393 deaths per million), Bulgaria (229 deaths per million), Italy (209 deaths per million), Spain (175 deaths per million), Cyprus (167 deaths per million) and Portugal (136 deaths per million). In addition, it is important to consider that Spain is the most affected country by heat waves across Europe.
Greater vulnerability of women and people over 80 years of age
In line with previous studies, the data show greater vulnerability in women and older adults. Specifically, after considering the general population, the heat-related mortality rate was a 55% higher in women that in men and an amazing 768% higher in people over 80 years old compared to those aged 65 to 79. For more information on these demographic phenomena, it is interesting to consult the article on the exposure of the population to heat waves.
Possible underestimation of the true burden of heat-related mortality
The study also warned that these figures may underestimate the true burden of mortality associated with heat. Due to the lack of availability of daily and homogeneous records during 2023, the team used weekly counts from Eurostat, which could contribute to this underestimation. Thus, it is estimated that the probable number of heat-related deaths in 2023 could have actually been approximately 58,000 deaths in the 35 countries studiedThis highlights the need for more rigorous monitoring of heat-related mortality.
Social adaptation to heat prevents up to 80% of mortality
One of the study's goals was to assess whether there has been a decrease in heat vulnerability in Europe, which is generally understood as an adaptation to rising temperatures. To do so, the team analyzed temperature and mortality data from previous periods (2000–2004, 2005–2009, 2010–2014, and 2015–2019). By inserting the 2023 figures into these models, it was calculated that if the temperatures recorded in 2023 had occurred in the 2000–2004 period, the estimated heat-related mortality would have exceeded the XNUMX temperatures. 85,000 deaths, that is, a Top% 80 to heat vulnerability in 2015-2019. This highlights the importance of implementing effective policies such as those discussed in the article on the heat island effect and its cost.
On the other hand, deaths in people 80 over years would have more than doubled, going from 1,102 to more than 2,200 deaths linked to heat, thus demonstrating that there has been substantial social adaptation to heat waves.
As highlighted Elisa Gallo, ISGlobal researcher and lead author of the study, “our results show how society has adapted to high temperatures during the current century, which has drastically reduced vulnerability to heat and the mortality burden of recent summers, especially among older people.”
Beyond the physiological limits of adaptation
Professor Joan Ballester Claramunt, principal investigator of the European Research Council (ERC) EARLY-ADAPT Consolidator grant, said: “In 2023, almost half of the days exceeded the 1.5°C threshold stipulated by the Paris Agreement, and Europe is warming at twice the global average. This threshold is likely to be exceeded before 2027, leaving us with a very small window of opportunity to act.”
It is urgent to implement strategies to reduce the mortality burden in the coming warmer summers and to provide detailed monitoring of the effects of climate change on vulnerable populations. These adaptation measures must be combined with mitigation efforts. by governments and the general public to avoid reaching tipping points and critical thresholds in temperature projections.
Forecaster.health, a tool for predicting mortality risk by sex and age
A recent web tool, Forecaster.health, has been launched by the research group responsible for the study. This platform provides predictions of mortality risk associated with cold and heat by sex and age. The tool is based on epidemiological models to estimate real health risks in 580 regions in 31 European countries. It is available free of charge (https://forecaster.health/) and provides forecasts up to 15 days in advance. This tool has the potential to be crucial in preventing heat-related deaths.
The EARLY-ADAPT Project
The study is part of the project framework EARLY-ADAPT, funded by the European Research Council, which aims to investigate how populations are adapting to the public health challenges posed by climate change.
Heat-related mortality in Spain
A team of scientists from the Institute of Environmental Diagnosis and Water Studies (IDAEA-CSIC) and the University of Valencia have developed an application called Heat Attributable Mortality in Spain (MACE)This tool uses data from the Daily Mortality Monitoring System (MOMO) and temperatures recorded by the State Meteorological Agency (Aemet) to calculate mortality attributable to moderate, extreme, and excessive heat from June to August.
The year 2022 was significant, with 3,012 heat-related deaths recorded during the 28 days of extreme heat. "During the summer of 2023, the third year with the highest heat-related mortality, 2,155 deaths were reported, after the heat waves of 2003 and 2022," he explained. Aurelio Tobias, IDAEA researcher and author of the study. This highlights the growing concern about the effects of extreme heat on public health, as well as the fact that temperature records in Spain have reached alarming levels. For more details on the situation in Spain, it is advisable to review the article that analyzes global warming in Spain.
La MACE It is updated daily and allows mortality rates to be calculated based on data from the last five years. This application not only facilitates data visualization but also promotes behavioral change by warning people about the impact of extreme heat on health.
Researchers emphasize that heat waves are one of the most evident effects of climate change, and the number of deaths attributed to them has increased in recent years. It is estimated that more than 153,000 additional deaths occurred globally between 1990 and 2019 due to heat waves. With the growing impact of climate change, an increase has been observed not only in the frequency but also in the severity of these phenomena. A recent report warns that without urgent action to mitigate climate change, there could be more than 2.3 million temperature-related deaths in Europe by the end of the century, highlighting the need for effective mitigation and adaptation policies.
