You are about to do something really big -- maybe a job interview, a presentation, a first date or your wedding -- and you notice that your palms and underarms are sweating. Perhaps, you've just completed an aerobic workout and your whole body is drenched in sweat. How can such different activities have the same effect on your body? What is sweat and why do we make it?

Perspiration, or sweat, is your body's way of cooling itself, whether that extra heat comes from hardworking muscles or from overstimulated nerves. In this edition of HowStuffWorks, we will examine your body's sweat glands, how sweat is made and what it does. You will learn that there is difference between the sweat on your palms and the sweat in your armpits and why your skin tastes salty after a workout!