The 3rd National Climate Change Adaptation Plan identifies adaptation to rising temperatures as a priority for the overseas departments and regions (DROM) in order to protect public health. This report presents an analysis of the influence of temperature on mortality in the DROMs (Guadeloupe, French Guiana, Réunion, Martinique, Mayotte) to describe risk levels and impacts and to support adaptation policies. The study covered the period 2014–2022. Time-series analyses were conducted for each DROM to model the influence of temperature on total mortality, by age group (15–64 years, 65 years and older) and by sex. The results were combined in a meta-analysis to derive estimators centered on each DROM, enabling the calculation of a fraction of mortality attributable to temperature. The median temperature was used to distinguish cold days from hot days. Several meteorological indicators were tested, yielding similar results, and the daily maximum temperature was selected for the main model. In all DROMs, a U-shaped temperature-mortality relationship was observed, with an increased risk of death for both cold and hot temperatures compared to the median. For cold temperatures (median), the risks of death are higher among those aged 65 and older and among women. Across all DROMs and the study period, 2,299 [1,503:3,160] deaths were attributable to cold temperatures and 1,805 [678:2,901] deaths to hot temperatures. Temperature is a significant health risk factor in the DROMs, with an impact that could worsen with climate change. Adaptation could rely on an early warning system and a prevention policy focused on the most extreme events, as well as structural measures to improve the overall health of the population and housing conditions, reduce exposure, and facilitate access to care.