Almost a quarter of adults age 69 and older may experience dangerous levels of heat worldwide by the mid-century, up from 14% today, according to a new study.
The study, which was published last week in the journal Nature Communications, projects that by 2050 there will be as many as 246 million more older adults exposed to extreme heat, defined as exceeding 99.5 degrees Fahrenheit. The most severe temperatures will be in the Global South, such as in Asia and Africa, though temperatures in North America are also expected to rise.
The projections emphasize an urgent need for policies and infrastructures to protect communities from the increased heat risk, said Giacomo Falchetta, the study’s first author and a researcher at the Euro-Mediterranean Center on Climate Change in Italy.
In a similar study co-authored by Falchetta and published in March, some parts of Texas were identified as vulnerable hotspots with both rising temperatures and a growing population of older adults. These areas included parts of Central Texas and rural communities in the southwest of the state. North Texas is projected to get hotter over the coming decades, but the aging population isn’t expected to grow as dramatically.
The number of Texans age 65 and older is expected to double over the next few decades — from 3.9 million in 2020 to 8.3 million by 2050. And triple-digit highs are expected to become the summertime norm for the state by 2036, according to a report by Texas 2036, a nonpartisan think tank. The extreme temperatures are threatening vulnerable populations in the Dallas-Fort Worth area, widening socioeconomic inequities and challenging the state’s emergency and health services.
Extreme heat is concerning for everyone but especially for older adults, said Dr. Angela Catic, an associate professor of geriatrics and palliative medicine at Baylor College of Medicine. Catic was not involved in either study.
“Older adults are more prone to heat stress and a lot of that is because of their chronic conditions, especially things like cardiovascular disease, diabetes, renal disease, kidney disease, obesity and medications that they take,” she said. “And then a lot of our older adults have cognitive and functional decline,” which can make it harder to understand the risk of heat or to take necessary precautions.
Medications like those used to treat high blood pressure, heart disease, mood disorders and neurodegenerative conditions like Parkinson’s disease interfere with the body’s ability to cool itself, an ability that typically declines with age, Catic said.
Even for healthy-seeming older adults, prolonged heat exposure could turn small, lurking health problems into larger, more devastating ones, said Karrie Curry, an assistant professor in the department of personalized health and well-being at the University of North Texas Health Science Center at Fort Worth. Curry was not involved in either study.
“In a normal person, when you’re exposed to higher heat or if you’re chronically hot, you do have a higher heart rate even at rest, which if you have plaque buildup or underlying stages of cardiovascular disease, that’s going to elevate your blood pressure even more,” she said.
In the latest study, Falchetta and his colleagues in Boston, Austria and Italy projected how different age groups will grow around the world. The projections were mapped onto a climate model that predicts what the Earth’s climate will be like in 2050.
The researchers then looked at two types of heat exposure: acute, or when extreme temperatures are brief, such as with a heat wave; and chronic, or when there are prolonged periods of uncomfortable heat, defined as more than 75 degrees Fahrenheit.
Falchetta and his colleagues projected that chronic heat exposure will increase globally by 2050. And, on average, the number of days where high temperatures exceed 99.5 degrees Fahrenheit will double, from 10 to around 20 days.
The recent studies demonstrate the need for more comprehensive and structured public health readiness, said Marcia Ory, a professor in the department of environmental and occupational health at the Texas A&M School of Public Health. Ory was not involved in either study.
Those who interact with older adults — whether family members, friends or other caregivers — need to have heat response plans, similar to emergency response plans for natural disasters, Ory said. Heat response plans may involve making sure older adults stay hydrated and, if needed, receive medical care or transportation to cooling centers or other places that provide shelter from the heat.
These plans could start at the state government level, but would be more effective at a local level, Ory said. Local community members can interact with local emergency medical responders, aging services, public health services and long-term care providers to ensure older adults get the attention they need.
“I think the key is that all units of government need to work together,” Ory said. “But [it’s] not just the government’s responsibility. Private philanthropy needs to work, too. We need to act now. It can’t wait until 2050.”
Efforts to bridge the heat inequality gap are more important than ever, Falchetta said. As of 2021, there were more than 54,000 renter households in Texas that didn’t have air conditioning, according to U.S. Census data. Even if most renters do have AC, it may not provide adequate cooling, KERA News reported in 2023. Among 20 of Texas’ largest cities, KERA found there was no single standard ordinance or regulation governing air conditioning for tenants.
“I do not believe this should be left up to individual responsibility. There is a real need to take action from a policy point of view,” Falchetta said.
Preparing for a safer, cooler future involves a range of solutions, he said, from energy subsidies to help pay bills to access to clean drinking water to designing more climate resilient and adaptive cities.
“It’s a systemic issue and the solution should be systemic, not just one solves all,” Falchetta said.
Miriam Fauzia is a science reporting fellow at The Dallas Morning News. Her fellowship is supported by the University of Texas at Dallas. The News makes all editorial decisions.
CORRECTION, 9:06 a.m., May 20, 2024: An earlier version of this story misstated the school where Dr. Angela Catic teaches. It is Baylor College of Medicine.
