Quantifying the Excess Burden of Cold-Attributable Cardiovascular Deaths in the United States

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Summary of  American Journal of Preventive Cardiology https://doi.org/10.1016/j.ajpc.2026.101514 
Dr. Pedro Rafael Vieira de Oliveira Salerno  et al.

Points

Researchers analyzed twenty years of data from over eight hundred U.S. counties and discovered that cold temperatures are responsible for a significantly higher percentage of cardiovascular deaths than heat.
The study found that roughly forty thousand excess heart-related deaths occur annually during cold months which accounts for over six percent of all cardiovascular mortality in the United States.
Extreme cold triggers physiological changes like blood vessel constriction and increased inflammatory processes that significantly raise the risk of heart attacks and strokes in vulnerable patients with chronic diseases.
While heat-related deaths totaled forty thousand over two decades the researchers estimated that cold weather caused eight hundred thousand excess deaths during that same twenty-year study period across the nation.
Experts recommend that public health organizations incorporate temperature forecasts into their emergency planning to better anticipate spikes in medical service calls and hospital mortality during extreme cold snaps.

Summary

This research evaluated the association between ambient temperature and cardiovascular disease (CVD) mortality across 819 U.S. counties, representing approximately 80% of the population over age 25. Utilizing data from 2000–2020, investigators identified a non-linear, lopsided U-shaped relationship between monthly mean temperatures and mortality rates. The primary objective was to quantify the burden of excess deaths attributable to non-optimal thermal environments, specifically comparing the physiological impacts of extreme cold versus extreme heat on systemic vascular outcomes.

The findings demonstrated that the minimum mortality temperature (MMT) was 23°C (74°F), with cardiovascular death rates increasing as temperatures deviated from this baseline. Cold weather was identified as the predominant environmental driver, accounting for approximately 40,000 excess deaths per year—representing 6.3% of all cardiovascular mortality. In contrast, hot weather contributed to approximately 2,000 excess deaths annually, or 0.33% of the total. Mechanistically, cold exposure induces sympathetic activation and peripheral vasoconstriction, which elevates blood pressure, increases myocardial oxygen demand, and promotes prothrombotic states and plaque instability.

The data suggest that populations with cardio-kidney-metabolic (CKM) syndromes are particularly vulnerable to temperature-related stress. While climate change discourse often prioritizes heat-related mitigation, these results highlight a substantial, overlooked mortality burden totaling 800,000 cold-attributable deaths over the 20-year study period. The researchers emphasize the need for health systems to integrate temperature forecasts into emergency planning and public health surveillance. Enhanced seasonal risk communication and targeted outreach for older adults could mitigate preventable cardiovascular events during sustained cold periods.

Link to the article: https://www.sciencedirect.com/science/article/pii/S266666772600108X?via%3Dihub

References

Salerno, P. R. V. D. O., Estrada-Mendizabal, R. J., Dong, W., Hum, A., Chen, Z., Capenter, C., Bassiony, M., Rajagopalan, S., Al-Kindi, S., & Deo, S. V. (2026). Cardiovascular disease mortality attributable to monthly non-optimal temperature in the united states: A county-level analysis. American Journal of Preventive Cardiology, 101514. https://doi.org/10.1016/j.ajpc.2026.101514