Think about it this way...in the wild, any cham is going to encounter rivals, potential mates, predators or other sorts of intruders. They fire up in response to stimuli. It won't kill them or such an ability would never have developed. What WILL matter is how often the need to fire up happens, and for how long. A cham who is forced to stay in "fire up" mode constantly is going to become exhausted and more likely to end up sick. Stress is part of life. Not all stress is bad, and not all is tolerable.