The hands and feet contain more sweat glands than any other part of the body. One square inch of skin on the palm of your hand may contain as many as three thousand tiny sweat glands.
But not all sweat glands are the same and sweat from different parts of the body is produced in different ways.
Working Hard, Getting Sweaty
When you're working hard, sweat forms mostly on your face and upper body while hands tend to sweat more under emotional strain. This is because the different sweat glands are activated in different ways.
One way is through the nervous system. When you're working hard or feeling hot, your body communicates those ideas to the brain by way of nerves.
In response, the brain sends messages back along the nerves to the sweat glands, telling them to increase the operation of the body's cooling system.
Hormones In Control
But a lot of the sweat glands are controlled by hormones instead of nerves. Most of these sweat glands are on the palms of the hands and the soles of the feet.
You've probably noticed that when you get frightened, your pulse rate increases and you feel instantly more awake. These changes take place because your body is producing more adrenalin, which controls a whole range of body functions including metabolism and heart rate.
Adrenalin is also the hormone most responsible for activating sweat glands. That's why if you get stagefright, your hands may be the sweatiest part of your body.
Sweaty, Nervous Feet
Since most of the hormonally controlled sweat glands, are on your hands and feet, those are the ones that are responding to the sudden increase in adrenalin.
Your feet are probably sweating too, but wrapped in shoes and socks they're more likely to be sweating anyway from warmth and so the added sweat from the adrenalin may not be as noticeable.