Heat- and cold-associated mortality in Germany, 2000–2023

BACKGROUND: The number of deaths in Germany attributed to heat has risen in recent years. At the same time, winters have become milder, which implies that there may be fewer deaths due to extreme cold. In this study, we estimated the mortality associated with both heat and cold in Germany for the years 2000-2023. METHODS: We used daily death counts and mean temperature records to estimate the percentage of heat- and cold-associated deaths for the years 2000-2023 by means of a generalized additive model (GAM). We also carried out a meta-analysis to estimate the effect of temperature on the relative mortality risk (exposure-response curve). RESULTS: We confirmed the recent increase in heat-associated mortality already reported elsewhere, while also documenting a decline in cold-associated mortality from approximately 2015 onward. As a result, overall temperature-associated mortality has fallen slightly over the past 10 years. We estimate that 4-5% of deaths are temperature-associated; typically, 3-4% are linked to cold, and just under 1% to heat. CONCLUSION: The slight decline in temperature-associated mortality does not imply that there is no cause for concern in the future, nor can it be simply extrapolated to future developments. Temperature-associated mortality reflects both the relative mortality risk at a given temperature and the number of days with that temperature. If the number of days with high temperatures continues to rise, adaptation strategies will have to be developed rapidly to prevent a marked rise in heat-related deaths.