A homeless woman, Irene (age 36) of Paterson, panhandles in downtown Paterson, New Jersey, in January 2019. Cold weather accounts for 65% of all temperature-related deaths in the US., a new study released Nov. 17, 2025, suggests.
Visitors eat warm breakfast at Hope Missions of the Upstate in downtown Anderson, S.C., Nov. 10, 2025. The Mission's building offers a warming center for residents.

Each summer, we hear about the deadly and very real danger of extreme heat. But perhaps we should be paying more attention to the impacts of wintertime cold.

Researchers have discovered that over the last 25 years, 65% of all temperature-related deaths were due to cold, while the remaining 35% were heat-related. Overall, in that period, some 69,256 U.S. deaths had extreme temperature exposure recorded as an underlying or contributing cause, according to a new study.

The findings are published in the Annals of Internal Medicine.

Deaths are largely preventable

“Our findings show that both heat and cold exposure continue to claim thousands of lives every year in the United States, deaths that are largely preventable,” senior author Shady Abohashem, of Mass General Brigham Heart and Vascular Institute, said in a statement.

The main message from the study, according to Abohashem, is that both heat and cold exposure continue to cause preventable deaths, and that these deaths are not distributed evenly. Adults 65 and older, men, and non-Hispanic Black individuals consistently face the highest risks from both hot and cold weather. "These patterns have remained stable for 25 years, underscoring the need for targeted protections for the most vulnerable groups."

The study breaks new ground because most prior research relied on forecasts or ecological models, and many examined heat and cold separately. He said, "Our study uses real, observed U.S. data spanning 25 years and looks at both heat- and cold-related deaths side-by-side, broken down by age, sex, and race/ethnicity. This gives a clearer, more up-to-date picture of who is most affected and where the biggest disparities lie."

We typically focus more on heat deaths than cold deaths. Should we rethink that?

According to Abohashem, heat is a growing concern due to climate change and absolutely deserves attention. "But our findings, and many global studies, show that cold exposure still accounts for more temperature-related deaths overall. Much of this is because cold-related deaths often occur on moderately cool days, not only during extreme events, and most are tied to worsening of chronic conditions rather than hypothermia itself."

"That said, climate change is rapidly shifting the balance," he said in an email to USA TODAY. "As highlighted in recent research, the relative burden is expected to move toward heat because heat-related mortality is rising faster than cold-related mortality is declining.

"So rather than shifting focus away from heat or cold, our public health efforts need to prepare for both hazards simultaneously (especially for high-risk groups), with growing urgency around heat as temperatures continue to climb," he told USA TODAY.

Are there hidden risks to cold weather?

Yes, according to Abohashem, cold exposure can worsen underlying medical conditions ‒ like heart disease, respiratory illness, and poor circulation, often without dramatic “extreme cold” events.

"Many of these deaths happen indoors in poorly heated homes, especially among older adults. Improving housing insulation, ensuring access to heat, and checking on vulnerable individuals during cold periods can make a real difference."

The National Weather Service has long said heat is the deadliest weather event in the U.S. Why the disparity?

The National Weather Service uses incident-based reports, often tied to specific acute weather events, he reports.

"Our study uses death certificate data, where a medical examiner records whether heat or cold contributed to a person’s death. Death certificates capture far more cases, including chronic or indirect effects, so the numbers are expected to be higher. These are two different metrics, each useful for different purposes."

The weather service chart shows far fewer cold deaths than heat deaths. In the past 30 years, the weather service says, the average number of heat-related deaths is 238 per year, compared to 38 per year due to cold. "That’s probably because the NWS only counts deaths tied to specific weather events, like heat waves or winter storms," he said.

"Most cold-related deaths occur quietly indoors or on moderately cold days and might not or never get reported to NWS, but they do appear on death certificates, which is why medical data consistently shows far more cold-related deaths," Abohashem said.

Were the results surprising?

"We expected older adults to be at higher risk, but the magnitude of the disparities, especially among men and non-Hispanic Black individuals, stood out," Abohashem said. "We were also struck by how consistent these gaps have been over time. It reinforces that temperature-related mortality is not only an environmental issue but also an equity issue."

This article originally appeared on USA TODAY: What's more dangerous, hot or cold weather? The answer may surprise you.

Reporting by Doyle Rice, USA TODAY / USA TODAY

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