The Cold Is Killing More Americans Every Year, Study Finds

Even as the climate warms, the cold is becoming a serious threat to Americans. New research this month shows that cold-related deaths in the U.S. have increased significantly over the past two decades.

Harvard Medical School researchers conducted the study, which aimed to better quantify deaths caused by cold temperatures in the United States. They found that the country’s cold-related death rate has more than doubled since the late 1990s, with deaths especially rising in recent years. Important risk factors for increased mortality likely include extreme weather events associated with climate change, homelessness and social isolation, the researchers say.

Extreme temperatures at either end of the thermometer can be life-threatening. Recent studies have shown that while heat-related deaths have increased in recent decades, cold weather tends to be generally fatal. A 2021 study found Cold was responsible for nearly three-quarters of global extreme temperature deaths in 2019, for example (an estimated 1.7 million deaths that year).

Harvard researchers note that cold-related deaths in the United States have only been minimally studied, and little is known about how the burden has changed over time. To address this knowledge gap, they analyzed death certificate data collected by the Centers for Disease Control and Prevention, focusing specifically on deaths in which cold was recorded as an underlying or contributing factor.

Between 1999 and 2022, more than 40,000 cold-related deaths occurred in the United States, the researchers found. After adjusting for age, they found that the death rate went from 0.44 cold-related deaths per 100,000 people in 1999 to 0.92 such deaths per 100,000 people in 2022. Much of this jump was the result of a significant annual increase in deaths through 2017. and 2022. The team was searching published This month in the journal clothes.

“Because of the undeniable nature of global warming there has been a rightful focus on heat deaths,” Rishi Wadhera, a cardiologist and public health researcher at Harvard, told Gizmodo in an email. “However, the results of our study serve as an interesting reminder that cold-related deaths also remain an important public health problem.”

Although their study was not designed to identify any specific reasons for this increase, Wadhera and his colleagues identified some possible reasons.

Climate change is known to increase both warming and risk Cold extreme weather eventsFor example. But it’s also possible that more Americans are at risk of being left out in the cold today than ever before, especially people in unstable living situations, Wadhera notes.

“For example, we know that the number of people who are unsheltered in the United States has increased over the past few years—it’s a population that is most exposed to outdoor weather, including cold snaps,” he said.

Homelessness levels in the US have generally increased since 2016 (the early years of the Covid-19 pandemic were a Notable exceptions(thanks in part to generous relief programs). In 2023, chronic homelessness has crossed The record number was set in 2007, when modern data collection efforts began, according to the Department of Housing and Urban Development (their report for this year has yet to be released). Substance use and social isolation can increase people’s risk of exposure to unsafe conditions, including temperature.

The team’s data showed some trends that show who is most vulnerable to cold-related death. Regionally, death rates were highest in the Midwest, where winters can be particularly brutal, for example. Among racial and ethnic groups, the highest death rates were seen among Native Americans and black Americans, respectively, and the highest death rates were seen among people over the age of 75.

The authors say more research is needed to unpack exactly why cold-related deaths are increasing. At the same time, there are already steps that policymakers can and should take to prevent this tragic loss of life, such as ensuring that vulnerable populations live in homes with reliable indoor heating or expanding access to warming centers.

“Our findings should raise awareness of the potential for injury and death from exposure to cold weather — especially for older populations with higher health conditions, homeless people who are most exposed to outdoor weather, and low-income populations who lack adequate access to indoor heating,” Wadhera said.