Cold weather kills far more people than hot weather: Lancet

After analysing over 74 million deaths in 384 locations across 13 countries, a global study has revealed that cold weather kills 20 times as many people as hot weather.

The findings, published in the prestigious journal The Lancet, also found that deaths due to moderately hot or cold weather substantially exceed those resulting from extreme heat waves or cold spells.

It is often assumed that extreme weather causes the majority of deaths, with most previous research focusing on the effects of extreme heat waves.

"Our findings show that the majority of these deaths actually happen on moderately hot and cold days, with most deaths caused by moderately cold temperatures," said lead author Antonio Gasparrini from the London School of Hygiene & Tropical Medicine.

The study analysed over 74 million deaths between 1985 and 2012 in 13 countries with a wide range of climates, from cold to subtropical.

Around 7.71 percent of all deaths were caused by non-optimal temperatures, with substantial differences between countries, ranging from around three percent in Thailand, Brazil and Sweden to about 11 percent in China, Italy and Japan.

Cold was responsible for the majority of these deaths (7.29 percent of all deaths), while just 0.42 percent of all deaths were attributable to heat.

The study also found that extreme temperatures were responsible for less than one percent of all deaths.

Mildly sub-optimal temperatures accounted for around seven percent of all deaths - with most (6.66 percent of all deaths) related to moderate cold.

Current public-health policies focus almost exclusively on minimising 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," suggested Gasparrini.