Sweating is an important mechanism for maintaining a normal body temperature in humans. It helps dissipate heat from the skin and keep it cool by transferring sweat to the air, where it evaporates away from the body. In this way sweating is a passive cooling system that does not require active participation or energy expenditure on part of the organism. However, if sweating is excessive—that is, when there is too much perspiration being lost from the skin—this can lead to overheating and dehydration with increased risk of developing hypothermia or hyperthermia (see below).
How do your core temperatures compare with ambient temperature?
The average human’s core temperature usually lies between 36°C and 37°C. Body surface temperatures vary somewhat but generally lie at about 37°C in healthy individuals who have been exercising slightly for a while. The most accurate methods of measuring these core temperatures are via impedance probes placed on fingers; they measure changes in electrical resistance across tissues as they warm up during exercise. These reflect variations in blood flow rather than any substantial change in tissue structure or amount due to increased metabolic activity such as might occur during sustained exercise, so thermoregulatory responses such as vasoconstriction (reducing blood flow) and shivering may be seen even though no net increase takes place in terms of actual tissue heating/cooling rates. Another method involves placing thermocouples under various parts of the body: