17 hours ago

Why more Americans are dying from the cold

On a warming planet, deaths in the United States related to cold weather are going up.

Although it may seem counterintuitive, new research shows that even as climate change fuels hotter temperatures, cold weather is becoming an increasing risk in the United States. As a second winter storm in a week is forecast to pummel parts of the United States, experts cautioned that risk factors making people more susceptible to the cold - such as homelessness and social isolation - are on the rise.

Subscribe to The Post Most newsletter for the most important and interesting stories from The Washington Post.

A study published last month in the journal JAMA found cold-related mortality rates more than doubled between 1999 to 2022, with almost all of the increase occurring in the past six years. The research also found that mortality rates were highest in the Midwest and among adults 75 and older, who are more susceptible to temperature extremes.

“We were really shocked,” Michael Liu, a fourth-year student at Harvard Medical School and the lead author of the study, said of the findings showing the rate of cold-related deaths had doubled.

“There’s rightfully been a focus on heat deaths because of the context of global warming. But both can be true,” Liu said of rising heat- and cold-related deaths. “Cold-related deaths are still a public health risk.”

The analysis found that in 2022, 3,571 people died of causes linked to cold weather, according to Liu. By comparison, heat-related deaths were lower - the Centers for Disease Control and Prevention recorded about 1,700 that year.

Another vast winter storm is expected to hit the central United States beginning late Wednesday, immediately following the season’s first widespread major winter storm, which brought hazardous conditions in the form of snow and ice from the Plains to the Mid-Atlantic over the weekend through Monday.

- - -

A ‘collision of risk factors’

It is difficult to identify and count cold-weather fatalities. The causes of death from cold weather vary widely, and it can take time for medical authorities to determine the cause of a heart attack or traffic accident. The same difficulties confront researchers trying to analyze trends in heat-related deaths.

What is apparent, however, is that some of the risk factors that can contribute to deaths from cold exposure are increasing.

Homelessness is on the rise in the United States, driven by higher rent costs and the widespread lack of affordable housing. An increase in migrants seeking asylum may also play a role. Recently, a federal report found that homelessness had reached its highest level on record, increasing by 18 percent in the 12 months ending in January 2024, the biggest one-year jump since the federal government began an annual count in 2007. The previous record was set in 2023, when homelessness rose 12 percent.

And like America overall, the homeless population is aging. Some cities are opening homeless shelters focused on senior citizens to address the growing crisis, but many are struggling to respond.

If living on the street, in a car or a tent makes people more vulnerable to hypothermia and frostbite, age further compounds the risk. With age, it becomes more difficult for the body to control its temperature, making it more susceptible to sudden cold snaps or heat waves. Older people are also more likely to have preexisting conditions, such as heart problems or respiratory ailments, that can be deadly in severe cold.

“You’re seeing this collision of risk factors that I think really predispose people to cold-related deaths,” said Liu, adding that more research is needed to understand how a person’s housing situation and income affect their risk.

The authors of the recent study wrote that other factors could also be contributing to the higher death rate, including social isolation and substance abuse. They found that cold-related death rates were highest among Alaska Native, American Indian and Black people, groups that are overrepresented in the nation’s homeless population. The authors also noted that these groups face disproportionate cold exposure due to a lack of home insulation or heating.

“You could have exactly the same winter weather as in the past and it makes sense that if you have more people living on the streets, or more people abusing drugs, you have more deaths,” said Gordon Giesbrecht, an expert on hypothermia and emeritus professor at the University of Manitoba. “It doesn’t need to be extremely cold for them to freeze to death.”

A 2018 study of cold-related injuries and deaths in New York City found that, among those who died of cold exposure from 2005 to 2014, most were exposed outdoors and about half of them were homeless. The majority of the deaths and illnesses took place outside of periods of extreme cold.

- - -

Untangling climate change’s role

Overall, winters are trending warmer. Between 1970 and 2024, U.S. winter warming averaged about 4 degrees Fahrenheit, according to an analysis by the research nonprofit Climate Central. The warming is most pronounced in the Upper Midwest, the Northeast and the Ohio Valley.

While there are still cold snaps, they are now about six days shorter, on average, the analysis found.

But climate change can also intensify extreme weather, and some scientists have raised the possibility that it may be contributing to fiercer snowstorms.

Another subject of hot debate: whether rapid warming in the Arctic may be altering atmospheric patterns and disturbing the polar vortex, an expanse of cold air that normally encircles the North Pole. This air can plunge southward, bringing frigid temperatures to places unaccustomed to it. But whether its behavior is affected by climate change is still ambiguous.

- —

How to protect yourself

Liu said he hopes the study’s findings are a wake-up call.

“People should be aware of how to protect themselves during extreme cold snaps. Have contingency plans. Stock up on groceries and supplies,” he said.

Experts said the first rule is simple: Don’t go outside. If you have to - if work or other obligations require it - then bundle up. Wear multiple heavy layers and cover any exposed skin to avoid hypothermia or frostbite, which can develop in minutes in extreme cold.

The first signs of frostbite are typically tingling or pain in the affected areas, often the extremities. If you notice signs of frostbite on yourself or someone else, such as a white or grayish-yellow skin area or skin that feels unusually firm or waxy, the CDC says to put the affected area in warm, not hot, water.

Acclimatization can help. People unaccustomed to severe winter weather struggle more, Giesbrecht said. Their bodies undergo more constriction, tightening blood flow to their extremities to keep their core temperature from getting cold. Though a protective response, this increases their risk of frostbite compared with someone used to icy temperatures whose skin does not get as cold.

Because older adults and people with poor circulation or other preexisting conditions are more vulnerable, experts also advise people to check on their neighbors, relatives and friends - especially those who live alone. Liu added that cities should do more to shelter homeless people during cold spells and bring people without sufficient access to heating to warming centers.

“It frankly feels so unacceptable that in the U.S., the vast majority of these deaths are completely preventable,” Liu said.