The idea of stress is solely dependant on one's definition of what stress is. In my experience what I would consider "my job" most people would consider extremely stressful while on the other hand, dealing with inter-office politics and niceties is not only stressful but tedious for me.
In those situations I refer to my prior training in precision firearms: inhale (through the nose), begin to exhale slightly then hold the breath in a relaxed state, aim (or focus) and then a slow steady squeeze of the trigger (or statement or action...whatever). From there you exhale fully.
The idea of hypervigilance (in severe cases "Freezing in place") in combat scenarios initiates from the first perception of a threat and the individuals inability or lack of confidence in one's self to deal with the threat. From there the body shuts down. The normal reaction to this type of stress is both psychological and physiological (increase in heart rate, tunnel vision, auditory lapses) but how you deal with the "stress" of the situation is based on how well you're trained for the situation. It's all about training yourself (mind, body and soul) for "the unexpected" when you reach a state of "no mind" and are able to adapt to whatever is thrown your way then you have mastered a stress free way of life.