Intuitiveness, attractiveness and efficiency are in general important characteristics of high quality User Interfaces (UI). In the case of a Mass Casualty Incident (MCI) and other life threatening situations good user interfaces are essential as every second counts in these time-critical situations. Finding the best way to interact with the system is a challenge with many open issues. Therefore, it is essential to test different UI alternatives to determine important usability issues as those mentioned before. This paper focuses on the research question how patients can be selected on a map application which runs on a rugged tablet PC. A rugged tablet PC is in general heavy because of its robustness, which introduces a new special requirement in addition to the existing UI requirements. The implementation and the evaluation of the UI alternatives presented in this paper were performed within the scope of the SpeedUp project1.