Sweat Glands

Humans evolved that way because changes in the climate 200,000 years ago that demanded that they travel long distances for food and water. | Humans also have an abundance of sweat glands, called eccrine glands. | Although there are other mammals that are hairless, humans are the only primates to have mostly naked skin. | This enabled them to obtain the food they needed to nourish their bodies and brains, while keeping them at the right temperature and allowing them to grow. | To make these glands more efficient, human bodies had to lose their hair to better dissipate heat.