http://goo.gl/477e5T
The response is helpful for warming up the muscles during "fight or flight" situations, such as when wild animals face their enemies; however, stress for people in today's society can last a long time and cause a chronic increase in body temperature, a condition called psychogenic fever, which brings on intense fatigue.
Now researchers published online in the Cell Press journal Cell Metabolism have identified a key neural circuit connection in the brain that's responsible for the development of psychological stress-induced hyperthermia and likely also plays a role in chronic psychogenic fever.