The palms of the hands and the soles of the feet contain more sweat glands than any other area of the body. The soles of the feet contain approximately 125 000 sweat glands on each foot.
The function of sweat:
keeps the skin on your feet moist and supple so it is able to withstand the stresses of walking.
increases friction on bare feet, this is thought to have helped our ancestors to increase the grip of feet on the ground when running from predators or any other threat.
helps to create an environment that is inhospitable to most disease-causing micro-organisms.