BackgroundClimate change significantly impacts health, particularly for individuals aged 65 and older, increasing heat-related illnesses and mortality. Understanding this burden is vital for public health planning.MethodsThis study analyzes data from the Global Burden of Disease (GBD) Study 2021, focusing on deaths, disability-adjusted life years (DALYs), and age-standardized ratios related to high-temperature exposure in individuals aged 65+ across 204 nations and territories. It examines trends from 1990 to 2021, assesses health inequities using measures like the Inequality Slope Index and Concentration Index, and projects future trends using a Bayesian Age-Period-Cohort (BAPC) model.ResultsIn 2021, there were 247,098 heat-related deaths globally among those aged 65+, with an age-standardized mortality rate (ASMR) increase from 26.3 to 27.1 per 100,000 (annual average percentage change (AAPC): 0.22). Aggregate DALYs reached 3,986,215, with the age-standardized DALYs rate (ASDR) rising from 419.6 to 526.7 per 100,000. South Asia and East Asia experienced higher burdens, while Oceania and Western Australia had lower rates. Lower-middle Socio-demographic Index (SDI) regions faced greater burdens, with absolute inequality increasing and relative inequality slightly declining. Non-communicable diseases (NCDs), such as ischemic heart disease and stroke, accounted for a significant proportion of heat-related deaths and DALYs, with upward trends. Projections indicate continued increases in deaths and DALYs by 2050.ConclusionsThis study highlights the growing global burden of high-temperature exposure on older adults, emphasizing regional disparities and the dominance of NCDs. These findings underscore the need for targeted public health strategies to address climate-related health risks in vulnerable populations.