An example of negative feedback from our bodies is when our temperature rises or falls due to exercise. When our body temperature rises above 98.6, which is the normal body temperature for the human body, our bodies will automatically do a few things in an effort to return to homeostasis.
Amongst these things our blood flow increases, sweating increases, temperature declines, and the body cools. These natural processes are put in place by the body in order to regulate our bodies to the conditions that they should be in. If, for some reason, the body does not perform these functions on its own outside measures should be taken.