Objective: To evaluate the effects of perioperative active warming on the core body temperature, postoperative pain, shivering and agitation in pediatric patients. Method: Children aged 2–6 years undergoing elective surgery, including orthopedic soft tissue surgeries, ear nose throat surgical procedures and general surgical interventions, all performed under general anesthesia, were randomized to receive either active warming (using the forced-air warming gowns, Bair Hugger, in the pre- and postoperative period, and a carbon fiber blanket in intraoperative period; Group A), or conventional warming using green blankets pre-and post-operatively and a carbon fiber blanket intraoperatively (Group B). Children undergoing emergency surgery, surgeries involving major body cavities (abdominal, thoracic, cranial surgery), or those with endocrinological pathologies, or baseline fever, were excluded. Core body temperature (t-core), postoperative pain, shivering and agitation scores were compared between the two groups. Results: Seventy children were included, with 35 in each group. No significant difference was observed between the groups in t-core values at 0 and 15 minutes preoperatively (P > 0.05). However, the value at 30 minutes preoperatively and all subsequent t-core values were higher in Group A (P < 0.001). Postoperative pain and shivering scores at 0 minutes, 30 minutes and 6 hours were significantly lower in Group A compared to Group B. No significant difference was observed in agitation scores in the immediate postoperative period, although, Group A showed reduced agitation at 30 minutes (P = 0.03). Conclusion: Active warming in the pre- and post-operative period significantly maintained higher core temperatures and reduced postoperative pain and shivering in children undergoing surgery compared to those receiving conventional passive warming measures in the pre- and post-operative period.