High-Reliability Organizations engage threats and adversity to maintain reliable operations. Human stress, fear, and threat responses drive safe and effective engagement of environmental threats. The executive functions integrate perception from opposite ends of the brain, hastily created plans, and motor activity. During a crisis, the hypothalamic-pituitary-adrenal (HPA) axis enables survival behaviors by releasing cortisol to "disarm" the executive functions. Novelty, uncertainty, and uncontrollability, in the domain of the executive functions, cause stress responses. Fear reactions at the subcortical level maintain a safe distance from the threat. Threat reflexes rapidly initiate protective behaviors. However, these same responses, when unmodulated, can harm the individual. The prevalence of unmodulated stress, fear, and threat makes them appear unpreventable, if not normal. This is the inherent vice of stress, fear, and threat. By describing their function and location in the brain, we can identify these behaviors to begin modulation for effective responses to threats.