NEW YORK (Reuters Health) - Cold temperature is to blame for the well-known winter peak in the incidence of sudden death due to cardiac causes, according to a new study.

The fact that cold temperatures increase blood pressure and put more strain on the heart is a possible explanation for the increased rate of sudden cardiac death during wintertime. Cold stress may also trigger processes that make blood thicker and increase its ability to clot, which can lead to cardiac events.

Investigators reporting in the Journal of the American College of Cardiology note that seasonality in heart disease events, with a winter peak and summer trough, has long been recognized. Yet, the role of weather conditions is unclear because most studies did not include weather data