The four factors of (1) physiological arousal caused by the stress of existing in what is commonly understood as a continual fight-or-flight-arousal condition, (2) cumulative loss of sleep, (3) the reduction in caloric intake, and (4) the toll of the elements—such as rain, cold, heat, and dark of night—assaulting the soldier all combine to form the “state of prolonged and great fatigue” that is the Weight of Exhaustion.
