The number of days when extreme heat makes it too dangerously hot to walk the dog, sweep the porch, and engage in other ordinary pursuits has doubled around the world over the last 75 years, according to new research. Scientists found that, on average, people aged 65 and older experience about a month each year when heat prevents them from carrying out routine activities.
Parts of Asia, Africa, Australia, and North America are becoming increasingly unlivable for senior citizens, the researchers said. Younger adults are also affected, losing roughly 50 hours annually as climate-driven heat restricts their daily lives.
Overall, more than a third of the global population now resides in regions where heat severely impacts everyday life, according to a peer-reviewed paper published Tuesday in the journal *Environmental Research: Health*.
While previous studies have documented the effects of extreme heat on human health, the authors of this new research say it is the first to highlight the consequences of rising temperatures on everyday activities.
“Extreme heat isn’t just affecting our ability to survive or work physically demanding jobs, but also just to do simple, light, daily tasks,” said Luke Parsons, a climate scientist at the environmental nonprofit The Nature Conservancy and lead author of the study.
### Methodology and Findings
The researchers analyzed heat and humidity records from 1950 to 2024. They used the United Nations’ Human Development Index—which measures each country’s health and living standards—as a proxy for vulnerability to rising temperatures. A physiological model of heat effects on different age groups helped determine when it becomes too hot for people to safely undertake tasks when exposed to outdoor temperatures in the shade.
In Qatar, for example, heat now makes it risky for older adults to engage in routine activities for about a third of the year. Even younger adults aged 18 to 40 must reduce daily tasks for more than 800 hours a year—that’s 10% of their time.
In the United States, senior citizens lose approximately 270 hours annually that could have been devoted to normal activities due to the risks of overheating. In the southern U.S., “we’re looking at many hundreds of hours of livability limitations for older adults every year,” Parsons said.
Regions such as southern Europe, southern South America, southern Australia, and parts of Asia and Africa have seen the largest increases in restrictions on daily life since 1995, according to the study.
### Impact on Workers and Vulnerable Populations
Jennifer Vanos, an associate professor at Arizona State University and co-author of the study who specializes in urban extreme heat, highlighted the risk overheating poses to workers engaged in low-exertion activities, such as restaurant staff who do a lot of walking on the job.
“Even though we don’t see that as high-intensity physical activity, it could turn into a very dangerous situation because of their exposure to heat over time,” she explained.
While citizens of wealthy nations such as Qatar and the United Arab Emirates can often find refuge in air-conditioned homes, Parsons noted that these countries rely heavily on large populations of migrant laborers working outdoors in construction and other sectors—populations especially vulnerable to extreme heat.
### A Grim Look at a Warming World
Global temperatures reached a record high in 2024, marking the first year to exceed 1.5 degrees Celsius of warming on an annual basis.
“This study provides us with a really grim, unfortunate glimpse into what a 1½-degree-warmer world potentially looks like,” Parsons said.
As extreme heat days increase, understanding and addressing the impacts on daily life—especially for vulnerable populations—will be increasingly critical in efforts to adapt to climate change.
https://www.latimes.com/environment/story/2026-03-10/extreme-heat-is-making-life-increasingly-unlivable