Why do some people suffer from the heat, while others tolerate it easily?

Tagesspiegel explains why the same temperature can be almost unnoticeable for one person and dangerous for another.

Ancestral Legacy

Modern humans originated in Africa, so our bodies are generally well-adapted to high temperatures. However, over millennia of living in different regions of the world, people have developed additional adaptations.

For example, researchers discovered a special mutation in the STC1 gene in representatives of the Turkana people, who live in arid regions of Kenya. It helps the kidneys continue to function normally even under severe dehydration and heat.

Павялічыць

Women from the Kenyan Turkana tribe often walk many kilometers daily in the heat to collect water for their animals and personal consumption. Photo: Simone Boccaccio / SOPA Images / LightRocket via Getty Images

Scientists believe that this genetic feature became particularly important about 5500 years ago, when the climate in the region became drier. People with this mutation had a better chance of survival and leaving offspring. According to research, they had, on average, about five percent more children than those who did not possess this genetic advantage.

Similar adaptations were also found in the semi-nomadic Daasanach people, who live in the region between Ethiopia, Kenya, and South Sudan.

Longer Legs Help to Cool Down

Not all adaptations to heat are linked to a single specific gene. Often, it's the result of many genes working simultaneously.

People whose ancestors lived in hot climates for a long time often have a more slender figure, as well as longer arms and legs. This body structure increases the body surface area relative to its mass, which allows for faster dissipation of excess heat into the environment.

Conversely, peoples who evolved in cold conditions, such as the Arctic Inuit, often have a more compact build and shorter limbs. This helps to better retain heat.

Why do people blush in the heat?

Regardless of where a person lives, their body strives to maintain a temperature of about 37 degrees Celsius. The thermoregulation system is responsible for this.

When the temperature rises, special receptors in the skin and blood vessels send a signal to the hypothalamus – the temperature control center in the brain. In response, blood vessels dilate, especially near the skin's surface. This is why the face and body blush.

The next stage is sweating. The evaporation of moisture from the skin's surface cools the body. This is one of the most important human features that has allowed our species to be active even in very hot climates.

You can get used to the heat

The ability to tolerate high temperatures is influenced not only by genes but also by life experience.

Many have noticed that during the first days of a vacation in a hot country, the heat seems unbearable, but after a week or two, the body reacts much more calmly. This process is called acclimatization.

During this process, the body teaches its thermoregulation systems to work more efficiently. A person continues to sweat, but the composition of the sweat changes: less essential salts and other electrolytes are lost with it.

Studies show that such adaptation can also be developed consciously. If one regularly spends time outdoors in warm weather, instead of hiding exclusively in air-conditioned rooms, the body gradually begins to cope better with the heat.

Павялічыць

But the body's capabilities are not limitless

Despite all protective mechanisms, extreme heat remains a serious threat to health and life. During prolonged overheating, the body can lose its ability to maintain normal temperature, leading to heatstroke.

Therefore, even those who consider themselves well-adapted to high temperatures should remember about water, shade, and reasonable limits. Because in the fight against heat, genes and training help, but they don't work miracles.

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