The effects of extreme heat may be more pronounced in young and middle-aged adults than in older adults

The extreme heat; a leading cause of weather-related death in the United States; poses a growing threat to the public, as days of extreme heat are expected to become more frequent, more intense and longer lasting due to the continuing effects of climate change. While the adverse health effects of heat have been well documented in the elderly, less is known about the potential effects of heat on young and middle-aged adults.

Today, a new study by researchers at the Boston University School of Public Health (BUSPH) found that complications from extreme heat appear to be more pronounced in young and middle-aged American adults than in adults. older.

Posted in British medical journal, the study examined the association between extreme temperatures and emergency department (ED) visits and found that extremely hot days were associated with a higher risk of emergency room visits from any cause. , heat-related illnesses, kidney disease and mental disorders among all adults, but the strongest association was among adults aged 18 to 64.

Previous studies on the health effects of heat have mainly focused on mortality or hospitalizations in the elderly. This study is the first nationwide assessment of the effects of extreme heat on adults of all ages, as well as the first national study to consider emergency room visits as a marker of the adverse heat effects on all adults.

Many illnesses that lead to the use of the emergency department do not result in hospitalization as they can be treated in a short time, especially among the younger adult population. By looking at emergency room visits, we sought to get a more complete picture of the true burden of illness that could be attributed to hot days. “

Dr. Gregory Wellenius, lead author of the study, professor of environmental health and director of the climate and health program at BUSPH

Wellenius and his colleagues analyzed anonymous data on health care use claims to quantify the risk of emergency room visits for any cause and for specific conditions potentially associated with rising temperatures during the hot season (between May and September) in nearly 3,000 US counties from 2010 to 2019.

The data was provided by OptumLabs, a collaborative research and innovation center with its core data assets linked in the OptumLabs Data Warehouse (OLDW). This database contains anonymized longitudinal health information; including medical and pharmaceutical claims, laboratory results and registration records; over 200 million registrants and commercial and Medicare Advantage patients, representing a range of ages and geographic regions across the United States.

For the study, the researchers analyzed data on complaints from 74 million adults, including more than 22 million emergency room visits. They found that days of extreme heat (varying by location, but averaging around 93 degrees Fahrenheit), were associated with a 66% increased risk of emergency room visits for heat-related illness, as well. at a 30% increased risk of kidney disease, compared to emergency room visits on cooler days. But the risk associated with extreme heat varied by age. An extreme hot day was associated with a 10.3% higher risk of emergency room visits in people aged 45 to 54, compared with a 3.6% higher risk in people over 75 years.

“Young adults may be at greater risk of exposure to extreme heat, especially among workers who spend a lot of time outdoors,” says lead author of the study, Dr. Shengzhi Sun, researcher at BUSPH Environmental Health Department. “Young adults also may not realize that they too can be at risk on extremely hot days.”

The results were also consistent with previous research which showed that residents of U.S. counties with lower warm-season temperatures still have a higher risk of heat-related complications. Extreme hot days were associated with a 12% increased risk of emergency room visits in the Northeast region and an almost 10% increased risk in the Midwestern and Northwestern regions, compared to 4.3 % in the warmer southeast.

“As extreme heat threatens everyone’s health, this study provides further evidence that it is particularly dangerous in areas with colder climates which may be less suited to heat,” says study co-author , Dr. Kate Weinberger, Assistant Professor at the University of British Columbia. School of Population and Public Health. “As temperatures continue to rise due to climate change, implementing heat adaptation measures in these regions will be of critical importance.”

Many of these heat-related complications can be avoided with policy changes that reduce heat exposure or improve people’s sensitivity and adaptability to heat, the researchers say, but they point out that the policies effective will differ among regions, states and counties.

“Although climate change is a global problem and heat threatens the health of everyone in the world, the impacts are felt locally and solutions must be tailored to local needs,” said Dr Wellenius, citing geographic infrastructure specific, vulnerability of the population, and available resources. “What works for heat wave preparedness in the Pacific Northwest is very different from what works in the Southeastern United States, so solutions need to be localized to meet the needs of the local community. “

By examining emergency department visits for different causes and for several age groups, we were able to accurately characterize the varying impact on the health of different populations, ”says study co-author Dr. Francesca Dominici, Clarence James Gamble Professor of Biostatistics at Harvard. TH Chan School of Public Health and Co-Director of the Harvard Data Science Initiative. “An important goal of this study is to provide actionable information to clinicians and public health experts on how to prevent these emergency department visits, also considering that we can anticipate when these episodes of extreme heat are likely to occur. happen. “


Boston University School of Medicine

Journal reference:

Sun, S., et al. (2021) Ambient heat and risks of emergency department visits in adults in the United States: time-stratified crossover case study. BMJ.

Previous As devices turn into services, what is ownership?
Next Amendment to Turtle Enactment a victory in turtle conservation efforts