Heat impacts the health of the elderly, but a recent study found that women are disproportionately more affected than men. In fact, the study revealed that women in their 40s are as vulnerable to heat-related health risks as men at the age of 65.

Earlier studies have shown that more women die from heat-related issues than men. In the latest study, the researchers at Penn State University further investigated the disparity and found that middle-aged and older women are physiologically more vulnerable to high heat and humidity than older men. The study noted that this increased risk is not solely attributed to women's longer lifespans.

Although the researchers did not directly compare middle-aged men and women, they found that middle-aged women's physiological responses to heat were comparable to those of older men, suggesting that women in this age group are more vulnerable to heat than men of the same age.

"Women between the ages of 40 and 64 are as vulnerable as men 65 years of age or older," the researchers noted. However, in adults younger than 30, the researchers did not observe any difference in heat vulnerability based on gender.

In the study involving 72 adult participants aged 40 to 92, researchers tested how different people handled heat in a special chamber. The participants had to swallow a small device that measured their core temperature throughout the trial.

They were then asked to perform light activities in the chamber, such as simple daily tasks, while researchers gradually increased the temperature and humidity until participants' core body temperatures rose. The rise in core temperature suggests that the body could no longer cool itself. Rising core body temperature can lead to heat-related illnesses, such as heat exhaustion, heat stroke, and death.

"In addition to demonstrating that middle-aged and older women are at greater risk from extreme heat, we also identified what levels of heat and humidity are safe for women as they age. This information is presented as a temperature/humidity curve based on a person's age, and it can be useful for setting policies designed to keep people safe during a heat wave," Olivia Leach, who led the study said in a news release.

"We're not saying that people who experience a certain temperature will necessarily become sick or die. We are identifying the limits of livability — the thresholds where people can no longer continue their daily lives unimpeded. Once people reach these temperatures, they need to take actions like seeking air conditioning to cool their bodies," said W. Larry Kenney, a researcher of the study.

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