This design case is about Emotional Design Theory in application to the design of pandemic face masks. As we know designers rely strongly on theoretical knowledge in making design moves. To understand how students may learn to apply theory, research was conducted to test the effectiveness of an assessment called Design CUE (Conceptual Understanding Evaluation). In this case, I describe the research study context and rationale for the development of the Design CUE as an instructional assessment used to teach emotional design to undergraduate students at a large midwestern research university. Emotional design is a threshold concept in design education developed by Norman; it identifies three levels of focus: visceral, behavioral, and reflective. This framework was presented in class and learner performance was evaluated through the completion of the Design CUE, the purpose of which was to transfer learning by bridging concepts learned in class to a design task. I report how the design succeeded in teaching emotional design theory but failed to initiate greater student creativity in applying theory, most notably in the visceral level of emotional design. I document the undergraduate course in which the design was used. I also provide the context of the research study which sought to understand if students could apply the theory of emotional design and how they incorporated emotional design into the design of pandemic facemasks.