mortality related to cold temperatures and mortality due to other factors that vary with season . Warmer temperatures do not always equate to lower winter mortality: many cold-related deaths do not occur during the coldest times of year or in the coldest places  but occur during the beginning or end of the winter season . Warmer US cities generally experience more mortality from extreme cold events and cold temperatures than colder cities in the USA and Canada . While mortality rates linked to direct cold exposure  is generally low, the relatively higher mortality during milder temperatures is thought to be largely due to respiratory infections and cardiovascular impacts , which, although correlated with temperature, may not be caused by cold temperatures . When separating the effects of cold temperatures from the effects of the winter season, one study found that cold temperature did not drive mortality and suggested that winter season excess mortality was due to seasonal factors other than temperature  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report