Fostering empathy enables designers to make more informed and inclusive decisions by understanding diverse populations’ perspectives and challenges. However, developing deep empathy for conditions one has not personally experienced can be extremely challenging. Empathy tools allow designers to step into the shoes of potential users to gain some understanding of their lived and felt life experiences. Such tools can provide valuable perspectives that evoke more intuitive, empathetic design outcomes, and yet there is a significant gap in the literature regarding the methodologies and processes involved in developing effective empathy tools. This paper presents a research through design case study focused on the development of a wearable empathy tool designed to simulate the experience of living with claw hand condition. Following an iterative design process informed by an autoethnographic approach, the aim was to comprehend and document the process of designing this empathy tool. By providing a real-world context of simulating a specific condition, this case study also illustrates a methodology for developing empathy tools based on literature review, state-of-the-art analysis, benchmarking, creative ideation, and iterative prototyping.