Background Many trainees complete rotations in intensive care units (ICUs), but little is known about how ICU rotations impact learners. Understanding residents' experiences in ICU rotations is a crucial step toward improving resident education and understanding the consequences, intended and unintended, of critical care learning. Objective We performed a qualitative study to understand how pediatric and emergency medicine residents experience a pediatric ICU (PICU) rotation. Methods For this phenomenological study, we explored residents' experiences with critical care learning by focusing on the high-stakes, emotionally charged PICU environment. Semistructured interviews were conducted with 12 residents after their first PICU rotation from July 2019 through March 2020. Data were analyzed through line-by-line coding, serial discussions, and consensus meetings. Finally, emergent themes and convergent narratives were constructed around the resident PICU experience. Results Residents perceived the PICU as a challenging environment for independent, self-driven, and active learning. They suffered adverse psychological effects, leading some to "give up" and many to experience feelings consistent with acute traumatic stress. Despite these challenges, residents described their PICU rotation as a "rite of passage" and reported increased comfort with caring for "sick kids." Conclusions Residents describe their PICU rotations as intense experiences that result in increased physician comfort. However, they also endure psychologically traumatic experiences that may hinder them, and the independent practitioners they become, from caring for certain types of patients in the future.