A new study has raised alarming concerns about the long-term effects of extreme heat on human health, revealing that it may accelerate biological ageing in older adults more significantly than smoking or drinking alcohol. As climate change continues to drive up global temperatures, experts are warning that excessive heat could pose severe health risks for seniors, particularly those living in areas that frequently experience high temperatures.
The study, published in Science Advances, shows how prolonged exposure to heat can have a measurable effect on the biological ageing process at the cellular level. Biological ageing, distinct from chronological age, refers to the deterioration of cells and tissues over time, which can increase the risk of diseases and early death. While previous research has focused on lifestyle factors like smoking, alcohol consumption, and lack of exercise, this study highlights the growing importance of environmental factors, especially extreme heat.
What Is Biological Ageing and Why Is It Important?
Biological age reflects the state of an individual’s cells and tissues, and it may be different from their chronological age, which is simply the number of years a person has been alive. As people age, cells and tissues begin to deteriorate, which leads to a higher risk of diseases like heart disease, diabetes, and Alzheimer’s. The higher someone’s biological age compared to their chronological age, the more vulnerable they are to these health issues.
In this study, researchers from the University of Southern California (USC) analyzed data from more than 3,600 adults aged 56 and older across the United States. They compared biological markers in participants’ blood samples with local temperature patterns to investigate the link between heat exposure and biological ageing. The results were startling: older individuals living in regions with frequent days above 32°C (89.6°F), a level classified as “Extreme Caution” or higher by the U.S. National Weather Service, showed signs of increased biological ageing. In some cases, their biological age was more than a year older than their chronological age.
The Role of Heat and Humidity
While heat alone poses a risk to health, scientists have found that humidity amplifies these dangers. Jennifer Ailshire, a professor of gerontology at USC and senior author of the study, explains that the combination of heat and humidity is particularly harmful to older adults. As people age, their bodies’ ability to sweat and cool down naturally decreases. In humid conditions, sweat evaporates more slowly, further reducing the body’s ability to regulate its temperature.
“The real issue is the combination of heat and humidity, especially for older adults. They don’t sweat the same way younger people do,” Ailshire said. “To truly understand your risk, you need to consider both temperature and humidity.”
Climate Change and Its Impact on Vulnerable Populations
The findings of this study are particularly concerning in light of the ongoing climate crisis. Global temperatures are rising at an alarming rate, with 2024 being recorded as the hottest year on record, according to the World Meteorological Organization (WMO). Heatwaves are becoming more frequent and intense, putting vulnerable populations, especially the elderly, at an even greater risk.
Previous studies have linked extreme heat to a variety of health issues, including cardiovascular stress, kidney damage, and cognitive decline. According to the World Health Organization (WHO), heat causes more than 175,000 deaths annually in Europe alone. Without intervention, the effects of climate change could lead to an additional 2.3 million deaths across Europe by 2099. However, this new research suggests that the elderly may face even greater risks than previously estimated.
“If everywhere is getting warmer and the population is ageing, these vulnerable individuals will need better protection,” Ailshire warned.
Urban Heat Islands and the Need for Action
Cities, where large populations of older adults live, are particularly vulnerable to extreme heat. Urban areas often experience higher temperatures than rural regions due to the concentration of buildings and human activity, a phenomenon known as the “urban heat island” effect. Researchers are calling for cities to take immediate action to reduce the impact of heat on vulnerable populations.
One potential solution is to increase green spaces in urban areas. Planting more trees, creating parks, and installing green roofs can help mitigate the effects of extreme heat by providing shade and cooling the air. Urban planning can also play a key role in reducing heat risks by designing infrastructure that helps regulate temperature, such as reflective surfaces and improved building materials.
Moreover, cities can implement early warning systems to alert residents to extreme heat events and provide cooling centers for seniors and other vulnerable groups. Public education campaigns that inform people about the dangers of heat and how to protect themselves can also save lives.
A Growing Public Health Concern
This study adds to the growing body of research that links climate change with public health risks. While the health risks of extreme heat have been recognized for some time, this new study underscores the need for immediate action to protect the elderly from the accelerating impacts of climate change.
As global temperatures continue to rise, it is crucial that policymakers and public health officials prioritize the well-being of older adults in their efforts to address climate change. The findings from USC’s study serve as a reminder of how urgent it is to protect vulnerable populations from the hidden dangers of excessive heat and humidity.
As the world faces an increasingly hot future, the need for adaptation strategies to safeguard public health has never been more pressing. Without action, the health of millions of older adults worldwide will continue to be at risk.
You can read more about climate change and its effects at New York Mirror.