Geographical Variations of the Minimum Mortality Temperature at a Global Scale: A Multicountry Study

Area of Science:

• Environmental Health
• Epidemiology
• Biometeorology

Background:

• Minimum mortality temperature (MMT) is crucial for understanding temperature-mortality links and local climate adaptation.
• Global data on MMT geographical variability is limited.

Purpose of the Study:

• To investigate the global geographical variability of MMT.
• To explore MMT associations with climatic and socioeconomic factors.

Main Methods:

• Utilized Poisson regression with distributed lag nonlinear models for MMT estimation in 658 communities across 43 countries.
• Employed mixed-effects meta-analysis to assess MMT variation by climate zone.
• Examined correlations with annual mean temperature and standard deviation.

Main Results:

• MMTs ranged from 14.2 to 31.1°C, generally decreasing with latitude.
• MMTs increased across climate zones: alpine (13.0°C) to tropical (26.5°C).
• Higher annual mean temperatures and temperature variability correlated with higher MMTs and lower MMT percentiles.

Conclusions:

• Mean annual temperature is a primary determinant of MMT geographical distribution and a proxy for population adaptation.
• Populations show adaptation to average temperatures, but potential for further adaptation exists.