Most often I'd stay away from people who exude negativity in the workplace, but now that I'm more educated about recognizing and personally handling going through a crisis, I'll be a lot more sensitive to any of the markers.
As taken from the previous class, ED400, someone who has burned out may eventually find themselves in a crisis.
I've found this when students cannot learn a new skill right away. As he or she sees her peers progressing, this may add pressure to the student and hinder further development. Usually I'll suggest taking a break and work on other things. If it involves a different skill set, this may give an effective break or even put the student ahead of the class and give more of a sense of control for learning the previous skill.