Människor som flyttar till varmare klimat lever mycket längre, och ökad dödlighet av minusgrader är ett mycket större problem än värmeböljor, enligt New York Times. Köld stressar kroppen.

Heat waves may receive more publicity, but it turns out that cold periods — days with an average temperature below 30 degrees —have more significant and longer-lasting effects on human mortality. More people die in cold periods than in homicides.

Extreme cold brings cardiovascular stress as human bodies struggle to adjust to the temperature; many of the deaths in these periods come through heart attacks. Heat waves tend to kill people who were already weakened and would have died soon anyway; cold periods bring additional people to the verge of death. When retired people move to a warmer state, their life expectancy rises dramatically.

Läs mer: So We Thought. But Then Again . . . - New York Times