Why do we perspire?
The sweat glands help keep you cool in the summer. When we get very warm, little beads of water called sweat form on our skin. Perspiration is a quick method of cooling off the body.
You can test this by wetting your hands and waving them rapidly. The water evaporates quickly and makes your hands feel cooler lowering the skin temperature.
A fan cools you because it creates a little breeze that makes the sweat evaporate quickly.
Our body heat remains at a certain temperature all the time. Perspiration is one of the ways our body is kept at a normal temperature.
When our body becomes to warm, the heat-control center of the brain sends signals to tiny tubes in the skin called sweat glands. They push sweat through tiny holes in the skin called pores.
As each little bead of sweat evaporates, it carries away a little heat. And you feel cooler. Sweat is mostly water mixed with salt.
We perspire in cool weather, too. But the small amount of sweat evaporates almost as soon as it is formed.-Dick Rogers