Why does excessive cold and heat threaten the lives of the elderly?

In 2003, the hottest summer in more than 400 years hit Europe, killing 70,000 people, most of whom were elderly. As people age, they are more affected by temperature, with summers being hotter and winters being colder. But why are heat waves dangerous for older adults? What can we do to minimize the next record summer death toll? As global warming makes extreme temperatures more likely, understanding how humans can beat heat waves is crucial.

When humans are hot, either after exercise or due to weather conditions, they release heat through evaporative cooling. However, by delivering large amounts of blood to the skin, they gain more cooling capacity, thereby dissipating heat into the environment. According to exercise physiologist Larry Kenney of Pennsylvania State University, "One of the unique things about humans is their ability to increase blood flow to the skin. When we have a cold, we pump a lot of blood into the skin, and the blood vessels dilate. This is why skin turns red when it's hot outside." For years, researchers around the world have been studying how aging affects our regulation of temperature, initially focusing on sweating. It turns out that we thought, as many people think, that older people cannot tolerate heat because of changes in the sweat glands on their skin. As skin ages and sweat glands shrink or disappear, they produce less sweat. As it turns out, this is not the case. It turns out that how much you sweat is related to your physical condition, how you adapt to the heat, and how you stay hydrated, not because of your age.

In hot weather, a person may draw up to 20 times more blood from the skin than in cold weather. But this is not the case for the elderly. As people age, they try to pump blood into the skin, but the blood vessels in the skin do not expand. Even if the blood vessels do not expand, the heart continues to forcefully pump blood. Therefore, heat stress can cause strain on the cardiovascular system and increase the burden on the heart. So most people who die during heat waves don't die from heatstroke or dehydration. They die from heart problems such as heart attacks or heart failure.