Magnetic resonance imaging (MRI) is widely used in pediatric patients and frequently requires sedation or general anesthesia. Both sedation and MRI-related environmental factors may influence thermoregulation. This prospective observational study aimed to evaluate body temperature changes in children undergoing MRI under sedation and to identify factors associated with these changes. A total of 285 pediatric patients (ASA physical status I-III) were included. Tympanic body temperature was measured immediately before sedation and after completion of MRI, and the temperature difference (ΔT) was calculated. Demographic, clinical, and environmental variables were analyzed to determine predictors of temperature change.