More women die in heatwaves, but biology 'isn't main cause'
In country after country, more women are dying from the heat than men. But researchers say biology isn't the main reason. Age, working conditions, and
In country after country, more women are dying from the heat than men. But researchers say biology isn't the main reason. Age, working conditions, and unequal access to rest may drive the gap. Observing recent heatwaves in Europe, one pattern has often been remarked on: More women appear to be dying than men. During Europe's then-record summer of 2022, a study found 56% more heat-related deaths among women than men, drawing on mortality data from 35 countries. Germany, which has just logged its deadliest heat season since 2016, with close to 9,800 heat-related deaths by mid-July, according to the Robert Koch Institute, is seeing the same pattern again this year. Are hormones making heatwaves more dangerous for women? Some of the recent coverage has leaned on the hormonal reading that women's bodies simply aren't equipped for heat. They sweat less, carry more body fat, and progesterone nudges core temperature up. But scientists who study the effect of heat on the human body say that's largely incorrect. "Overall, studies usually show only slightly more vulnerability to heat in women compared to men," saidAlexandra Schneider, an environmental epidemiologist and deputy director of the Institute of Epidemiology at Helmholtz Munich. "It's not really a very strong signal." The small differences that do exist are real: Women do have a lower sweat rate, less skin area relative to body size, and fat distribution that affects thermoregulation. Hormones play a role too, but unevenly across a lifetime. Schneider points to one group in particular: Women past menopause, when cardiovascular risk climbs. Older women with existing heart disease, she says, are probably at the highest risk of all.
But even in those cases, she doesn't think biology is the main cause for the extra deaths during a heatwave. "The living conditions, the social environment where women live, makes probably even more of a risk than just the differences in hormone status." How to survive heat waves in the city To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video A research gap, not a biological difference Toby Mündel, a kinesiology professor at Brock University in Canada, who studies extreme human environments, says that the impact is "overstated," when asked whether there's a real biological basis for the claim that women are more likely to die in heatwaves. The factors that most determine how a person copes with a heatwave, Mündel says, are age, body size, fitness and habitual activity, and not biological sex. Sweating is one example. Even though women do sweat less, that doesn't make them more vulnerable, because they compensate in another way. "They send blood flow to the skin, vasodilation, much better than males do," Mündel says, meaning their blood vessels widen more efficiently, moving heat to the surface where it can escape. Pregnancy, which many assume must be dangerous, is another example. "As a woman progresses through pregnancy, she actually becomes better at handling heat," Mündel says. He draws a clear line between physiology and circumstance: There are good reasons not to have pregnant women doing heavy outdoor labor in extreme heat. But their bodies aren't the reason. Why does the data suggest otherwise? Partly, Mündel's argument is based on what gets measured. Studies often count hospital and emergency admissions, and women are far more likely than men to seek medical help.
The BriefWire