You sweat, or perspire, to cool off the extra heat your body makes. If you could not sweat, your temperature would be so high that it could kill you. Your body lets this heat escape through your skin by sweating. Your sweat glands, all 2,000,000 of them, are spread out all over the surface of your body.
But certain areas of your body have larger sweat glands than other areas. Your armpits, your palms, the soles of your feet, and your forehead have these larger sweat glands, so you will probably feel yourself sweating in these areas the most.
An inactive person with a sit-down job may give off up to 1 quart of perspiration a day, while an active person doing hard physical labor may give off as much as 20 quarts!