Cold Is Deadlier Than Heat

CC BY 2.0. Antoine K

A shocking 17 times more people die from cold than heat each year, according to Lancet study.

It sounds surprising, when you consider how much media attention is given to heat waves, but this is the result of a study published in The Lancet in 2015. Researchers analyzed the deaths of over 74 million people in 384 locations worldwide, including Australia, Brazil, Canada, China, Italy, Japan, South Korea, Spain, Sweden, Taiwan, Thailand, UK, and USA. They found that extreme temperatures, whether hot or cold, were not nearly as dangerous as “milder but not optimal weather.”

Temperature played a role, directly and indirectly, in 7.71 percent of all deaths studied. Most of these (7.29 percent) occurred when the temperature was colder than the “optimum temperature” – defined by the New York Times as “the temperature in each country that is associated with the lowest death rate” – while only 0.42 percent of deaths were linked to temperatures above the optimum. In other words, the relentless chill of a moderate winter is the real killer, far more than extreme temperatures, for which people are better prepared.

How does cold kill?

One of the reasons why cold can be fatal is that climates with moderate winters are not cold enough to force them to build well-insulated and heated homes. As a result, homes in places like the southeastern United States can be far chillier than their counterparts in the northeast.

This doesn’t surprise me. I’ve never been so cold during winter as when I moved from Canada to Sardinia, Italy. Even though the temperature rarely dipped below freezing, the house was not properly insulated, nor heated, which meant that it always felt chilly and damp inside. My home in Canada, by contrast, was an oasis of warmth, with its fireplace, furnace, and thick insulation.

When people feel cold, they are more susceptible to heart attacks, pneumonia, flu, and strokes. The researchers stated that blood clots and blood pressure are both likely to increase when it’s cold. People also tend to congregate indoors in wintertime, increasing the likelihood for disease infection. Then there are the obvious accidental deaths, such as slipping on ice and fatal car crashes in snowstorms. The New York Times adds:

“There are also far more fire-related deaths in cold weather, resulting from faulty or overtaxed wiring, improper use of indoor heaters and errant sparks from fireplaces. With windows and doors closed and tightly sealed to keep out the cold, the risk of carbon monoxide death also rises.”

Despite these findings, extreme heat warnings continue to garner much attention from the media. Warnings about staying indoors, keeping hydrated, using air conditioning, and taking advantage of urban cooling stations abound, compared to warnings about wearing one’s woolies and staying by the fire. Perhaps the weather reporters should take a look at this study.