This is due to the body's tendency to maintain homeostasis.
Homeostasis is resisting change in order to maintain a balanced internal environment. Since the bodily function is constantly experiencing change, it has to regulate and maintain the balance. Sweat is an example of a process meant to maintain body temperature.
For homeostasis to occur, the body must be subjected to negative stimulus such as a body temperature exceeding [tex]37^{o}C[/tex]. The negative loop is then created by other body functions to counteract the effect of the stimulus. In the case of temperature, the negative loop produces sweat resulting in lower body temperature.
