Regulating affective responses to acute stress has the potential to improve health, performance, and well-being outcomes. Using the biopsychosocial (BPS) model of challenge and threat as an organizing framework, we review how appraisals inform affective responses and highlight research that demonstrates how appraisals can be used as regulatory tools. "Arousal reappraisal," specifically, instructs individuals on the adaptive benefits of stress arousal so that arousal is conceptualized as a coping resource. By reframing the meaning of signs of arousal that accompany stress (e.g., racing heart), it is possible to break the link between stressful situations, and malignant physiological responses and experiences of negative affect. Applications of arousal reappraisal for academic contexts and clinical science, and directions for future research are discussed. [This is the online version of an article published in "Emotion Review".]