Found an error?
Report now
Sweating helps regulate body temperature and protects the body from overheating. However, as we age and during prolonged periods of heat, the sweat glands become less effective. (File photo)
Keystone
Annoying, but essential: Sweating regulates body temperature. Where people sweat the most, how long it takes to get used to the heat, and what happens when the body’s own “air conditioning” stops working.
The human body has between two and four million sweat glands, according to the University Hospital of Zurich (USZ). Most of these are located on the soles of the feet, with a density of up to 370 per square centimeter. Only the lips and the glans of the penis lack sweat glands.
The main function of sweating is to regulate body temperature. When the fluid on the skin evaporates, it draws heat away from the body, thereby protecting it from overheating. At least half a liter of sweat evaporates every day. In the process, the body loses not only fluid but also important salts, magnesium, and other electrolytes.
According to the USZ, children under the age of five, people with chronic illnesses, and older adults are particularly at risk during heat waves. As people age, the function of their sweat glands declines. During prolonged heat, the glands can also become exhausted, which increases the risk of overheating.
According to the German science program “Quarks,” the body can adapt to new climatic conditions: In an unusually hot and humid environment, you initially sweat more. After about three weeks, the body has acclimated. In the process, it also learns to conserve resources, as sweat produced by an acclimated body contains less salt. Regular sauna visits can also help train the sweat glands.
Sweaty hands when excited are a remnant of human evolution, as “Quarks” explains. For human ancestors, sweat on the hands was useful because it made the skin more grippy. This made it easier, for example, to climb trees. Today, this bodily reaction often occurs in stressful situations, such as during a job interview.
Stress- or anxiety-induced sweat cannot evaporate from the cool skin surface, as heat-induced sweat would. Instead, the droplets run down the skin, which is perceived as “cold sweat.”
Fresh sweat is odorless. The typical body odor only develops when skin bacteria break down the secretions from the scent glands. An individual’s bacterial flora determines the odor.
Men’s sweat often smells stronger because bacteria break down the byproducts of the hormone testosterone. According to “Quarks,” teenagers’ sweat can smell as soon as it is secreted due to the release of hormones during puberty. A genetic variation (ABCC11) causes many people of Asian descent to release very few of the substances responsible for the odor.
The smell of sweat also plays a role in mate selection. If two people are genetically similar, they are more likely to find each other’s sweat odor unpleasant. According to the USZ, this is a natural mechanism designed to prevent reproduction between individuals with a similar gene pool.
Both excessive and insufficient sweat production can lead to health problems. In hyperhidrosis, the glands produce sweat even when the body does not need to cool down. In Switzerland, about two to four percent of the population is affected by this condition.
The opposite condition is anhidrosis, in which sweat production is impaired. This is particularly dangerous for those affected, especially in high temperatures, because the body lacks an important cooling mechanism.
15.07.2026, 10:01
