The Safety-Critical UX - Method Selection Scheme (SCUX-MSS) is introduced as a novel framework for evaluating User Experience (UX) methods specifically within safety-critical work environments. Traditionally, UX has been underexplored in such contexts, with emphasis typically placed on usability. This research addresses the gap by developing a tailored method selection scheme that aids practitioners in selecting appropriate UX methods for their specific needs. Built on a systematic literature review and expert interviews, SCUX-MSS categorizes methods across five distinct layers, simplifying the evaluation process. The framework was validated through a focus group of safety-critical environment experts, who highlighted its practical applicability and potential to enhance the integration of UX in these complex settings. SCUXMSS aims to bridge the methodological divide, providing a robust tool for applying UX methods in safety-critical domains.