About half a liter of water is lost through the skin every day. We do not become aware of this and this is called insensible perspiration.
This sweating does not originate in the sweat glands, but results from diffusion through the skin layers.
Real sweating begins when the temperature rises, or when you do hard work. Then watery secretions emerge from the skin's millions of pores. It is possible to sweat away 11.4 liters in 24 hours.
If such heavy sweating goes on for a long time, it may be harmful. If the sweat does not evaporate as fast as it forms, it loses its cooling effect.
Heavy sweating also reduces the amount of vital salts in the body. Since sweating makes you thirst, you will be forced to drink more water, which will further dilute the salt reserves of the body.
