The effects of heatwaves on health are much more diverse than previously thought. In addition to well-known issues such as heatstroke and dehydration, extreme temperatures seem to be associated with over 30 other conditions and types of injuries, according to a new study.
Europe has faced successive waves of extreme heat this summer, causing thousands of deaths and putting pressure on healthcare systems. While heatstroke, heat exhaustion, and dehydration are the most well-known effects of heatwaves, a new study published in Science Advances shows that high temperatures are linked to over 30 other health problems, including worsening multiple sclerosis, skin rashes, and various injuries, as reported by Euronews.
“It is a public health obligation to protect individuals and communities most vulnerable to the harmful effects of climate change. If we only focus on heat-related illnesses that are already well-known, we will underestimate the true burden of extreme temperatures on health, which could lead vulnerable individuals and communities to be overlooked,” says the study's author, Hyojung Jang, from Northwestern University in the United States.
The study analyzed 1,803 diagnoses recorded during nearly a million visits to emergency departments and urgent care centers in Chicago between May and September, from 2011 to 2023.
Researchers identified several conditions associated with high temperatures that are often overlooked in emergency services. These include skin rashes and swelling, acute kidney failure, multiple sclerosis, psychiatric and behavioral disorders, as well as insect bites and stings.
The authors emphasized that urban environments face additional risks due to the so-called “urban heat island effect,” which can raise local temperatures by several degrees and prolong the duration of heatwave episodes.
Heatwaves could also be associated with more accidents and acts of violence
The results also suggest that extreme temperatures may be linked to an increase in accidental and violent traumas, including assaults and incidents involving firearms. Researchers identified 23 specific diagnoses related to injuries, poisonings, or other external causes that met the criteria to be considered heat-related.
“Previous research has shown that when people are exposed to extreme temperatures, they tend to behave more aggressively, and this could play a role here as well. When it is very hot outside, the body is under stress, but the mind is also affected. This can distract attention or accentuate irritability and, consequently, could lead to more accidents,” explains Daniel Horton, co-author of the study and associate professor at Northwestern University.
The study's findings could help medical systems better prepare for future heatwaves. Researchers recommend that clinical alerts take into account a wider range of conditions, including kidney problems and fluid imbalances in the body, which can occur even days after exposure to extreme temperatures. Thus, emergency services could better anticipate the increase in the number of patients during and after heatwave periods. However, the authors stress that the results, based on data from Chicago, need to be confirmed in other populations and climatic zones.
C.S.