This study employs a user-centered design approach to address preschool children’s emotions during common illnesses. Through interviews with pediatric medical experts (each with at least five years of clinical or teaching experience) and a survey of 114 Taiwanese parents raising children aged three to six, we explored key challenges and scenarios in pediatric visits. The expert discussions covered six topics, including common childhood illnesses, emotional care strategies, and the accuracy of interactive information. Findings highlight that acute respiratory infections and injuries are the most prevalent illnesses, with critical intervention points identified from symptom detection to post-consultation care. We propose four key interactive features: 1) symptom self-reporting, 2) health education, 3) medical records, and 4) therapeutic games, to aid parents in managing their children’s emotional and physical well-being. This study also consolidates design strategies for emotional care, enhancing parent-child relationships, and interdisciplinary design practices. Future implementation in pediatric clinics and home settings will further validate the proposed approach.