The number of hospitalizations increases with the onset of heat, with the province of Zaragoza leading the way.

Extreme temperatures affect health to such an extent that in the worst case scenario they can cost lives. Every summer we tell how deaths increase due to the health effects of heat, but What is the relationship between high temperatures and specific reasons for hospitalization?

Investigation conducted by ISGlobal. analyzed more than 11 million hospitalizations in 48 Spanish provinces from June to September over more than a decade.between 2006 and 2019. Using different models, they estimated the relationship between temperature and different causes of hospitalization for the summer season and by province.

Their results, published in the journal Environmental Perspectives, show that lHigh temperatures increase hospitalizations for obesity, kidney and urinary failure, and sepsis.among other reasons.

By province, Zaragoza tops the list with increase in the likelihood of hospitalization during extreme summer temperatures compared to comfortable temperatures by 16.6%, although this investigation did not delve into the reasons. Although the study analyzed temperature and hospitalization data by province, the factors that may have led to these results were not examined. To find out this will require a special study.

Double your income

The group of diseases in which the effects of heat are most noticeable when admitted to hospital are metabolic disorders and obesity. In these cases, the risk of hospitalization on the hottest days increases almost twice compared to days of optimal or comfortable temperature. “Intense heat combined with insufficient fluid intake can cause dehydration, which can damage the kidneys, lead to the formation of kidney stones and increase the risk of urinary tract infection,” explained Hisham Achebak, ISGlobal researcher from Inserm (France) and co-author of the study, in an information session organized by the Scientific Media Center of Spain. “In obese people, heat loss through sweating is prevented by fat deposits, which act as an insulator. and makes them more susceptible to heat-related disorders,” he added.

The research team also calculated average daily temperatures, average daily relative humidity and concentrations of various air pollutants. Days with high air pollution levels appear to exacerbate the risk of heat-related hospitalisation for metabolic disorders and obesity, as well as diabetes.but not in other health indicators. For its part, relative humidity did not seem to play a significant role in the association between heat and emergency hospitalization, except in the case of the risk of acute bronchitis and bronchiolitis, which was higher on days with lower relative humidity.

“We observed that the additive effects of heat waves—or extremely high temperatures over consecutive days—were small and specific to a subset of diseases, mostly nonrespiratory infectious diseases, endocrine and metabolic disorders, or diseases of the nervous system, among others. For this reason we believe that Existing heat early warning systems must be activated not only during heat waves, but also during variable temperature extremes.“Says Joan Ballester Claramunt, ISGlobal researcher and final author of the study.

What happens to the body

“The underlying mechanisms by which heat causes adverse health effects remain unclear but appear to be related to “the way our body regulates its own temperature”explains Hisham Achebak, a researcher who has been awarded a Marie Skłodowska-Curie postdoctoral fellowship by the European Commission. “Under conditions of thermal stress,” he adds, “the body activates vasodilation of the skin and sweat production in order to lose heat.” The subsequent reactions “may affect people differently depending on factors such as age, gender or pre-existing health conditions.” For example, we know that women have a higher temperature threshold, above which “they activate sweating mechanisms and are more susceptible to the effects of heat.”

The study found significant differences by age and gender. Although heat increased the risk of hospitalization in all age groups, The most vulnerable groups were children under 1 year of age and over 85 years of age.with an increased risk of hospitalization. Moreover, Achebak notes that “on the hottest days, men were at higher risk of hospitalization for injuries than women,” which he attributes to “risky behaviors, such as more outdoor work.” They had a higher risk of hospitalization for parasitic, endocrine and metabolic, respiratory, or urinary diseases.