Prominent theories suggest that time and number are represented by a common magnitude system. However, distinct patterns of temporal and numerical processing occur in the presence of emotional stimuli, calling into question theories of a common magnitude system, while also unveiling questions regarding the mechanisms underlying these temporal and numerical biases. We tested whether numerical processing, like temporal processing, may be impacted by increased arousal levels, yet have a higher threshold level in order to impact estimates. If so, then induced arousal may reverse the typical pattern of numerical underestimation in the presence of emotions. Adults (N = 85) participated in either a stress-induction or a control version of the task. Then, participants completed a numerical bisection task in the presence and absence of emotional content. Increasing arousal had no impact on numerical processing, except in the presence of happy faces, providing further evidence for distinct processing mechanisms.