Overview
- The nationwide study of 2000–2020 county data across 819 U.S. locations, published Tuesday with ACC.26, estimates about 40,000 extra cardiovascular deaths each year tied to cold.
- Heat still raised risk but to a much smaller degree, with about 2,000 additional cardiovascular deaths per year across the same period.
- Researchers identified an optimum temperature near 23°C (74°F) and a lopsided U‑shaped pattern, with mortality rising on both sides and climbing far faster in colder months.
- Older adults and people with diabetes, heart failure, or chronic kidney disease face higher risk because cold constricts blood vessels and sparks inflammatory responses.
- The analysis used monthly, population‑level data, which the authors note as a limit, and they plan a follow‑on study linking daily temperatures with EMS activations to refine short‑term risk estimates.