Effects of Hot Nights on Mortality in Southern Europe

Background: There is strong evidence concerning the impact of heat stress on mortality, particularly from high temperatures. However, few studies to our knowledge emphasize importance hot nights, which may prevent necessary nocturnal rest. Objectives: In this study, we use hot-night duration and excess predict daily cause-specific mortality in summer, using multiple cities across Southern Europe. Methods: We fitted time series regression models summer including natural, respiratory, cardiovascular causes, 11 four countries. included a distributed lag nonlinear model with lags up 7 days for night adjusted by mean temperature. summarized city-specific associations as overall-cumulative exposure–response curves at country level meta-analysis. Results: found positive but generally between relative risk (RR) nights. RR associated nonaccidental Portugal was 1.29 (95% confidence interval [CI] = 1.07, 1.54); other were imprecise, also estimates Rome Madrid. Risk ranged 1.12 CI 1.05, 1.20) France 1.37 1.26, 1.48) Portugal. consistently higher than duration. Conclusions: This study provides new that, over wider range locations, indices are strongly deaths. Modeling thermal characteristics during nights could improve decisionmaking preventive public health strategies.