Cold Weather a Bigger Killer Than Heat, Study Finds

But moderate, not extreme, temperatures more deadly, researchers say

By Robert Preidt

Thursday, May 21, 2015

THURSDAY, May 21, 2015 (HealthDay News) -- Cold weather kills 20 times more people worldwide than hot weather, a new study shows.

In addition, deaths caused by moderately cold or hot weather far exceed those from extreme cold or heat, the researchers reported in the May 20 issue of The Lancet.

"It's often assumed that extreme weather causes the majority of deaths, with most previous research focusing on the effects of extreme heat waves," lead author Antonio Gasparrini, of the London School of Hygiene & Tropical Medicine in the United Kingdom, said in a journal news release.

"Current public-health policies focus almost exclusively on minimizing the health consequences of heat waves. Our findings suggest that these measures need to be refocused and extended to take account of a whole range of effects associated with temperature," Gasparrini concluded.

The research team looked at more than 74 million deaths that occurred in 13 countries between 1985 and 2012. The countries in the study included a wide range of climates. Nearly 8 percent of all deaths were temperature-related. About 3 percent of deaths were temperature-related in Brazil, Sweden and Thailand, the study found. In China, Italy and Japan, about 11 percent of deaths were related to temperature.

Cold caused about 7 percent of all deaths worldwide. Heat caused just 0.42 percent of deaths, the findings showed.

Extreme temperatures caused less than 1 percent of all deaths, the study found. Nearly 7 percent of deaths were caused by moderately hot or cold temperatures, with most caused by moderate cold (6.6 percent), the researchers said.

The authors of an accompanying editorial, Keith Dear and Zhan Wang, from Duke Kunshan University in China, were concerned that the study didn't include information of susceptibility to temperature changes. Socioeconomic status, age and air pollutants could increase susceptibility, they said.

"Since high or low temperatures affect susceptible groups such as unwell, young and elderly people the most, attempts to mitigate the risk associated with temperature would benefit from in-depth studies of the interaction between attributable mortality and socioeconomic factors, to avoid adverse policy outcomes and achieve effective adaptation," they explained.

SOURCE: The Lancet, news release, May 20, 2015

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