Winter chill kills 20 times more people than hot weather

London: When it comes to death toll due to weather, cold winters claim 20 times more lives than hot summers, finds an international study.

The research, which analysed over 74 million deaths in 384 locations across 13 countries, also revealed that deaths due to moderately hot or cold weather substantially exceed those resulting from extreme heat waves or cold spells.

Lead author Dr Antonio Gasparrini from the London School of Hygiene and Tropical Medicine in the UK, said that while it's often assumed that extreme weather causes the majority of deaths, with most previous research focusing on the effects of extreme heat waves, their findings show that the majority of these deaths actually happen on moderately hot and cold days, with most deaths caused by moderately cold temperatures.

Around 7.71 percent of all deaths were caused by non-optimal temperatures, with substantial differences between countries, ranging from around 3 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 1 percent of all deaths, while mildly sub-optimal temperatures accounted for around 7 percent of all deaths--with most (6.66 percent of all deaths) related to moderate cold.

According to Gasparrini though current public-health policies focus almost exclusively on minimising the health consequences of heat waves, their findings suggest that these measures need to be refocused and extended to take account of a whole range of effects associated with temperature.

The study is published in The Lancet.