Through sweat glands and superficial blood vessels, the skin is able to cool the body and regulate its internal temperature.
The eccrine sweat gland, which is controlled by the sympathetic nervous system, regulates body temperature. When internal temperature rises, the eccrine glands secrete water to the skin surface, where heat is removed by evaporation.
If all the plants on earth died, so would the people. ... When green plants make food, they give off oxygen. This is a gas that all animals must breathe in order to stay alive. Without plants, animals would have no oxygen to breathe and would die.