THURSDAY, Nov. 20, 2025 (HealthDay News) -- Heat- and cold-related mortality account for about 0.1 percent of total U.S. mortality, according to a study published online Nov. 18 in the Annals of Internal Medicine.Ibrahim Hassan, M.D., from Suez Canal University in Egypt, and colleagues examined long-term national trends in mortality associated with heat and cold temperature from 1999 through 2024 in the United States.The researchers identified 69,713,971 U.S. deaths between 1999 and 2024, of which 0.1 percent had temperature exposure recorded as an underlying or contributing cause of death (35 and 65 percent heat- and cold-related, respectively). Per 100,000, the crude mortality rates were 0.30 and 0.56 for heat and cold. The adjusted mortality rates in 2024 were 0.30 and 0.43 for heat and cold, respectively, with overall annual percentage changes of 1.93 and 1.95 percent, respectively. In the latter years, crude results suggested a potential modest increase in mortality. Higher temperature-related mortality was seen for older adults (65 years and older) and males compared with their respective counterparts in demographic-specific analyses. The highest heat-related adjusted mortality rates were seen for non-Hispanic Black people, with more than twofold higher rates than those of non-Hispanic White people (0.41 versus 0.19; rate ratio, 2.19). Cold-related adjusted mortality rates were highest for non-Hispanic Blacks, followed by non-Hispanic Whites, and Hispanics (0.71, 0.43, and 0.23, respectively)."The results help us understand which populations may be disproportionately affected so public health strategies can shift accordingly," coauthor Shady Abohashem, M.D., M.P.H., from Massachusetts General Hospital in Boston, said in a statement.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter