Two interruption handling strategies were distinguished based on experimental data. Reactive strategy implies an immediate switch from the main task after the onset of interruption. Proactive strategy relies on investing additional processing in the creation of a stable, interference-resistant representation of the main task. It is shown that in the though proactive strategy is associated with longer transition from the main to the additional task, it can also lead to quicker additional task execution and main task resumption. It is concluded that proactive strategy can be more effective in the long run. Selection of an appropriate interruption handling strategy is determined by the perceived cognitive complexity of the interruption episode.