Background: Climate change is accelerating heatwave frequency in cold-climate regions, yet cold exposure remains the dominant driver of temperature-related mortality. This shift creates uncertainty regarding future health burdens, compounded by the historic lack of preparedness for extreme heat by local population. To clarify these competing risks, we conducted a systematic mapping review of temperature-related mortality across cold-climate countries.
Method: To synthesize heat and cold effects and identify research gaps, we evaluated temperature-mortality associations in cold-climate countries (1990–2026). We searched Scopus, Web of Science, and PubMed, identifying 9,135 articles; supplementary searching added 1,693.
Results: After screening, 117 studies met inclusion criteria, predominantly from Canada (n = 41) and Sweden (n = 39). Of these, 83 assessed full temperature–mortality exposure–response relationships, 42 assessed extreme temperature events, and 8 examined both approaches. Cardiovascular and respiratory diseases dominated cause-specific analyses. Across the mapped literature, cold-related cardiovascular risks were frequently reported as greater than heat-related risks, while evidence for respiratory mortality was heterogeneous and often limited by small numbers of deaths.
Discussion: Key gaps included: (1) geographic bias toward milder regions, underrepresenting polar and continental areas; (2) methodological inconsistencies in extreme event definitions and lag specifications; and (3) limited non-cardiorespiratory cause-specific evidence. This review identifies critical methodological and geographic gaps, establishing a foundation for future quantitative assessments of temperature-mortality associations in cold-climate populations.