Switching between two concurrent tasks is an important ability of the mind. In a series of two experiments, we explored the role of activation (arousal and subjective significance) and emotional valence in shaping the effectiveness of switching between two cognitive tasks: gender-marking and emotional categorisations of verbal stimuli. We expected arousal to disrupt and subjective significance to boost the effectiveness of cognitive switching. We employed a paradigm that allowed us to present emotional words and measure the reaction latencies when a task given to the participants was switched; thus, the response was more costly than when continuing to respond to the same task. The first experiment, conducted with neutral words, showed that high subjective significance reduced reaction latencies in comparison with medium subjective significance. The second experiment showed a similar pattern only for neutral stimuli in the emotional categorisation task, but not for negative and positive stimuli. We did not find a clear effect of arousal or valence. The results of our studies suggest that subjective significance is independent of arousal in enhancing the cognitive control resources.