Colds Kill More Americans Every Year, Study Finds

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

Harvard Medical School researchers have conducted a study that aims to better estimate deaths caused by cold weather in the United States. They found that cold deaths in the country have more than doubled since the late 1990s, with deaths especially high in recent years. According to the researchers, important risk factors for increased mortality may include extreme weather events associated with climate change, homelessness and social isolation.

Extreme temperatures at either end of the thermometer can be life-threatening. Although recent studies have shown that heat-related deaths have increased in recent decades, cold weather is generally more deadly. 2021 study found for example, that cold was the cause of nearly three-quarters of global extreme temperature deaths in 2019 (there were a total of 1.7 million deaths that year).

The 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 a primary or contributing cause.

Researchers found that between 1999 and 2022, there were just over 40,000 cold-related deaths in the United States. After adjusting for age, they found that the death rate rose from 0.44 cold deaths per 100,000 in 1999 to 0.92 in 2022. Much of this jump is the result of a significant annual increase in deaths between 2017 and 2017. and 2022. These were the team’s findings has been published in the magazine this month JAMA.

Lead study author Rishi Wadhera, a cardiologist and public health researcher at Harvard, told Gizmodo in an email that “heat-related deaths are warranted given the undeniable nature of global warming.” “However, the results of our study serve as a striking 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 highlight some possible factors.

Climate change is known to increase both heat and risk cold extreme weather eventsfor example. Wadhera notes that more Americans today are at higher risk of being left out in the cold, especially those with unstable living conditions.

“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 the population most exposed to outdoor weather, including cold weather,” he said.

Homelessness in the US has generally increased since 2016 (the early years of the covid-19 pandemic a notable exceptionthanks in part to generous aid programs). Chronic homelessness in 2023 exceeded According to the Department of Housing and Urban Development, record numbers in 2007, when modern data collection efforts began (their report for this year has yet to be released). Substance use and social isolation can also increase people’s risk of exposure to dangerous conditions, including heat.

Certain trends emerged in the team’s data showing who was more susceptible to cold-related deaths. Regionally, the death rate was highest in the Midwest, for example, where winters can be particularly brutal. Among racial and ethnic groups, the highest death rates were among Native Americans and black Americans, and the highest death rates by age were those over 75 years of age.

More research is needed to clarify why cold deaths are increasing, the authors say. At the same time, there are steps policymakers can and should take to prevent these tragic losses of life, such as making sure 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 more health conditions, homeless people who are most exposed to outdoor weather, and low-income populations without access to adequate outdoor air conditioning.” indoor heat,” said Wadhera.