Rescue workers are often confronted with situations that can elicit strong emotions. To remain capable of acting in emergency situations and to maintain mental health in the long term, high self-regulatory demands are placed on rescue workers. Research shows that rescue workers particularly rate disgust and sadness stimuli in valence as less unpleasant compared to individuals who are not continuously confronted with emergency situations (Völker & Flohr-Devaud, 2021). However, it remains open, which fundamental processes lie behind this reduced emotional reactivity and to what extent the findings can be transferred to the dimensions of potency and activation. In the present study, the emotional reactivity of rescue workers (n = 65) was examined on the dimensions of valence, potency, and activation and compared to a comparison sample (n = 65) without medical experience. Special attention was paid to habituation and emotion regulation processes. For this, responses to repeatedly subliminally presented images that normatively elicit disgust, sadness, and fear were compared with responses to previously unpresented images in two emotion regulation conditions. Compared to the control group, rescue workers reacted less intensely to disgust and sadness stimuli and habituated more strongly to these stimuli. Emotion regulation and habituation proved to be two functionally independent processes. Thus, the reduced emotional response of rescue workers can be attributed to habituation processes. Although habituation is often described as a non-associative process, the repeated categorization of similar stimuli seems to play a central role.