Extreme heat, which is a primary cause of weather-related mortality in the United States, is becoming a greater concern to the public as days of extreme heat are predicted to grow more frequent, more intense, and longer-lasting as a result of climate change’s ongoing consequences.

Although the negative health effects of heat have been well documented in elderly people, less is known about the effects of heat on young and middle-aged people.

A new study conducted by Boston University School of Public Health (BUSPH) experts has discovered that the effects of extreme heat appear to be more pronounced in young and middle-aged Americans than in elderly ones.

PublishedThe study, which was published in The British Medical Journal, looked at the link between extreme temperatures and emergency department (ED) visits. It found that days of extreme heat were associated with a higher risk of ED visits for any reason, heat-related illness, renal disease, and mental disorders among all adults, but the strongest link was found among those aged 18 to 64.

Previous research on the health effects of heat has mostly focused on death or hospital admissions among the elderly. This is the first national-scale assessment of the consequences of high heat on adults of all ages, as well as the first national study to look at emergency department visits as a marker of heat-related harm in all people.

Dr. Gregory Wellenius, professor of environmental health and director of BUSPH’s Program on Climate and Health, and colleagues investigated anonymous healthcare utilization claims data from 2010 to 2019 in nearly 3,000 US counties to quantify the risk of ED visits for any cause and for specific conditions potentially associated with rising temperatures during the warm season (between May and September).

OptumLabs, a collaborative research and innovation center with its core connected data assets in the OptumLabs Data Warehouse, provided the data. This database provides de-identified, longitudinal health information on more than 200 million commercial and Medicare Advantage users and patients across the United States, including medical and pharmaceutical claims, laboratory findings, and enrollment records.

For the work, the scientists studied claims data among 74 million adults, including more than 22 million ED visits. When compared to ED visits on cooler days, they discovered that days of excessive heat (varying by region but averaging about 93 degrees Fahrenheit) were associated with a 66 percent greater risk of heat-related illness and a 30 percent increased risk of kidney disease. However, the dangers of intense heat differed by age. A day of excessive heat was linked to a 10.3 percent higher risk of ED visits in those aged 45 to 54, compared to a 3.6 percent higher risk in those aged 75 and up.

“Younger adults may be at greater risk of exposure to extreme heat, particularly among workers that spend substantial time outdoors,” said study lead author Dr. Shengzhi Sun. “Younger adults may also not realize that they too can be at risk on days of extreme heat.”

The findings were also in line with prior research, which found that those living in US counties with lower warm-season temperatures are nonetheless at a higher risk of heat-related problems. Days of high heat were linked to a 13 percent rise in ED visits in the northeast, and a roughly 10 percent increase in the Midwest and northwestern regions, compared to a 4.3 percent increase in the milder south east.

“As temperatures continue to rise due to climate change, the implementation of heat adaptation measures in these regions will be critically important,” said study co-author Dr. Kate Weinberger, assistant professor at the University of British Columbia’s School of Population and Public Health

Many of these heat-related issues can be avoided by implementing policies that decrease exposure to heat or enhance people’s susceptibility and adaptability to heat, according to the researchers, although they stress that successful policies will vary by region, state, and county.

“Although climate change is a global problem and heat threatens the health of everybody across the world, the impacts are felt locally, and the solutions have to be tailored to local needs,” said Dr. Wellenius, citing geographic-specific infrastructure, population vulnerability, and available resources.

“What works for heat wave preparedness in the Pacific Northwest is really different from what works in the southeastern US, so the solutions have to be localized to accommodate the needs of the local community.”

Source:10.1136/BMJ-2021-065653

Image Credit: iStock

You were reading: Younger adults are at greater risk of exposure to extreme heat than the elderly, study shows