Spells of extreme cold kill over 27,000 Americans each year, or about 700 people each very cold day. ... 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. In fact, 8 to 15 percent of the increase in American life expectancy over the last 30 years comes from people moving to warmer climates, according to research done by two economics professors, Olivier Deschenes at the University of California, Santa Barbara, and Enrico Moretti, at the University of California, Berkeley.
--Tyler Cowen, NYT, on why we should retire to Arizona