Older adults are vulnerable in a warming climate. Better buildings could help protect them

In 2003, during Europe’s worst heat wave in centuries, almost 15,000 people died in France. About three-quarters of those deaths occurred indoors, and approximately 80% of the people who died were over 75, an age at which people tend to be less capable of perceiving heat and less well-equipped to adapt to it.

In the coming years of mounting climate change, people around the world — particularly older adults — are expected to be similarly vulnerable. But though scientists know a lot about heat, from how it can cause long-term organ damage and death to how some populations are more susceptible than others, they know less about how it impacts people indoors in their own homes.

That’s what Amir Baniassadi wants to change.

Baniassadi, who was recently named a 2023 STAT Wunderkind, is dedicated to learning more about how the built environment affects the health and well-being of older adults. As a postdoctoral researcher at the Marcus Institute for Aging Research at Harvard Medical School and a consultant at the Harvard Graduate School of Design, Baniassadi works with doctors, architects, and engineers to assess heat vulnerability and how buildings could be constructed to mitigate risk as global temperatures rise.

“This is a new reality,” Baniassadi said. “There are people who are going to be hurt. How do we make them hurt less?”

For as long as Baniassadi can remember, he wanted to be a scientist. As a child in Tehran, Iran, he was curious about everything; at the library, he chose books about planets and stars. His mother, however, kept him firmly tethered to earth. An environmental engineer who studied wastewater treatment and management systems, she drove him to school and told him about the environment. Baniassadi grew up knowing the names of oceans and the causes of Iran’s water crisis.

He soon began to study the environment more formally: After getting a bachelor’s in mechanical engineering and a master’s in energy systems engineering, Baniassadi moved to the U.S. to pursue a Ph.D. in civil, environmental, and sustainable engineering at Arizona State University.

In the lab of David Sailor, a mechanical engineer, Baniassadi began modeling how to make cities and buildings more energy efficient. “Super cool” materials like porous polymer coatings could save double the energy compared to traditional white roofs; hybrid roofs could combine advantages of green roofs, made with water-retaining vegetation, and high-albedo roofs, which are reflective.

After his first year, Baniassadi also began using models to predict what would happen inside existing buildings during a heat wave or power outage and how that could affect older adults in Houston. It was the first time he’d used engineering to study vulnerable populations, and the first time he’d had to bridge so many fields at once, working with geologists, epidemiologists, and urban climatologists.

At a conference in 2018, Baniassadi met Holly Samuelson, an architect and associate professor at the Harvard Graduate School of Design. The two struck up a conversation around their shared interest in heat vulnerability, and how they might collaborate.

“In the building industry, we do lots of simulating buildings to think about how they’re going to perform both in terms of energy and thermal performance,” Samuelson said. “But we don’t have great details about behavior and building, especially for elderly building occupants, or especially for building occupants who are mildly cognitively impaired.”

Together, they could answer those questions. Baniassadi came to Harvard to work for Samuelson as a postdoctoral fellow, studying how different building characteristics impacted heat vulnerability in Boston.

While Baniassadi was adjusting to Boston, Lewis Lipsitz, a geriatrician and director of the Marcus Institute for Aging Research at Hebrew SeniorLife who’d soon become his mentor, was uncovering new questions about the city where he’d lived for years.

At a retirement community run by Hebrew SeniorLife, one resident — a former engineer in his 90s — had recorded different environmental measurements throughout the campus. There was too much background noise from fixtures like heating fans and blowers, which prevented people who are hard of hearing from communicating easily. Temperatures and humidity inside the buildings were often too high or too low, which could dehydrate residents and leave them more susceptible to infections.

To Lipsitz, that was a wake-up call. For a retirement community, NewBridge on the Charles is exceptionally beautiful, with multi-story windows that let in natural light, an aquatic center, a garden, and walking trails that weave along the river. But even in a place where architects seemed to have thought of everything, the resident’s data showed that older adults were living in a world that wasn’t optimized for them.

“After speaking with him, we realized that we should really be studying what is the optimal environment for older people,” Lipsitz said. “We realized we should be educating architects and designers and contractors who build housing for seniors to change their standards so that they make them conducive to good health.”

Lipsitz teamed up with Brad Manor, an associate scientist at the Marcus Institute, and Samuelson, the architect. Together, they laid out plans for a study of older adults in their homes. To do that, they’d need someone who could communicate between their worlds. Samuelson knew just that person.

Discussing the project over Zoom, Baniassadi grew excited. He thought of his grandfather, who’d died of severe Alzheimer’s, and how frustrated Baniassadi had been by how little he could help. He remembered how, during the summer when their second-floor apartment in Tehran was cooler than his grandmother’s, she’d struggled upstairs to stay with them despite her bad knee.

With his grandparents on his mind, Baniassadi agreed to join the project.

Suddenly, after years in front of a computer, Baniassadi was speaking to the people inside the kinds of buildings he’d modeled. And he was terrified.

He’d never found it easy to socialize with new people, and English was not his first language. He imagined all the ways things could go wrong. An older person could have severe memory problems. Their adult child could be protective and defensive.

But Peggy Gagnon, a nurse and coordinator of the clinical study, walked him through the process of reaching out to study participants and what to do in potential worst-case scenarios. After about a year, those interactions felt natural, and he grew comfortable around study participants, and they around him.

Soon, Baniassadi, Lipsitz, and Manor developed a way to monitor both the environmental variables and health conditions of participants, and tested it in a group of older adults. They installed sensors to measure air temperature, humidity, and carbon dioxide concentration in residents’ homes. They also gave participants smart rings to record their heart rhythms, breathing rate, and skin temperature, and asked them to answer smartphone-based questions about their well-being. At the end of the trial period, just over 100 days, they’d shown it was possible to collect data in a new way. Before, they’d monitored conditions in a laboratory setting; now, they were recording what it was really like in people’s homes, and capturing data from people who might not have been able to travel to a lab.

Working with people, every data point felt new. “Until you go there and talk to people to realize, OK, there’s an actual person, sitting there, and this is how it feels with my young body to be in that room —,” Baniassadi said. “It gave me a lot of perspective.”

He remembers an older woman who kept her home so cold that he didn’t want to take off his jacket when he visited her. She’d slept more poorly than almost anyone in their study.

By contrast, on one hot July day, Baniassadi visited the apartment of a 93-year-old man who sat in his chair in his underwear, the curtains drawn against the sun as the indoor temperature climbed above 85. Baniassadi, then 30 years old, was sweating through his T-shirt. He knew the older man must have been suffering. “You could see that it was really having an impact on his body,” Baniassadi remembered. But the man refused to turn on his air conditioning. He was saving money.

Before, Baniassadi had been attuned to the physical components of a space — the location of its windows and the way the air circulated through them, the kind of air conditioning the builder had installed. Air conditioning was a binary; either you had it or you didn’t. Now, he sees a network of variables that affect a person’s exposure to heat or cold, including their socioeconomic status, cognitive function, and personal history.

Baniassadi said that his personal encounters with study participants have changed the way he thinks about data and the connections between exposures and outcomes. “It’s still the same statistical analysis, but the way you look at the problem, the way you conceptually make a model of what’s happening in your mind, it becomes very different.”

Already, Baniassadi, Lipsitz, and Manor have found a range of temperatures for optimal sleep for older adults, between 68 and 77 degrees, with sleep quality dropping off at lower and higher temperatures. Not only was the best temperature for sleep different for different people, but the shape of the curves — each person’s sensitivity to temperature changes — varied, too.

Manor hopes that their work will lead to adaptive environments, homes that respond to the needs of individual occupants. A smart thermostat, for example, could adjust a bedroom’s temperature in response to a ring on a person’s finger monitoring their sleep.

“To me [this] is just a really exciting area, a largely untapped area, of actually controlling a home based upon the individual’s biology,” he said.

Baniassadi, meanwhile, hopes to start his own research group, likely in academia, where experts from different fields convene to discuss ideas for improving climate resiliency among older adults.

“The way we think, design, and operate our houses, I think it’s … built for a different climate,” he said. “But that doesn’t mean that we can’t do it better.”

Amir Baniassadi is part of the 2023 class of STAT Wunderkinds. Read more about this year’s rising young stars in science and medicine.