And that means when we contract our skeleton muscle, for example when I'm contracting, when I'm moving my hand the skeleton muscle inside my hand is contracting and that increases the blood flow as well as the lymph flow inside the vessels of our body. Now when our skeletal muscles contract they also release a good deal of energy, of energy that we cannot actually use. And so the way that our body gets rid of this energy is by releasing it is by dissipating it in the process of sweating. Now if we're outside and it's very cold outside, what our body does, the hypothalamus basically induces our somatic nervous system to essentially contract our skeletal muscle. And what this does is it increases the amount of energy that is released and that increases the temperature of our body. It basically helps maintain the core temperature of our body at 36.7 degrees Celsius.