69,000 Deaths from Extreme Temperatures in the US

Extreme heat and cold have been responsible for over 69,000 deaths in the United States over a span of less than 30 years, from 1999 to 2024. This equates to one death per 1,000 from all causes, according to a study led by researchers from Mass General Brigham in Boston, published in the Annals of Internal Medicine.

The study, as explained by senior author Shady Abohashem, a faculty member at Harvard Medical School, provides a comprehensive national assessment of deaths related to non-optimal temperatures at both extremes, including key demographic subgroups. Previous research often examined heat and cold-related deaths separately.

Researchers analyzed data from the Centers for Disease Control and Prevention's WONDER platform, focusing on death certificates that listed temperature as a contributing or underlying cause, based on clinical codes.

Between 1999 and 2024, there were 69,713,971 deaths in the US, with 69,256 (1 in 1,000) attributed to extreme temperatures—35% related to heat and 65% to cold. Recent years have seen higher mortality rates linked to temperature.

"Our findings show that exposure to both heat and cold continues to claim thousands of lives annually in the US, deaths that are largely preventable," Abohashem stated. "While most temperature-related deaths are still due to cold exposure, heat-related deaths are expected to rise with accelerating climate change."

The study found that older adults (65 and over) and men had higher temperature-related mortality rates. Black individuals experienced the highest heat-related mortality rates, more than double those of white individuals. Cold-related mortality rates were also higher for Black individuals, followed by whites and Hispanics.