Study objective: First-aid guidelines recommend the administration of cool running water in the early management of thermal injury. Our objective is to analyze the associations between first aid and skin-grafting requirements in children with burns. Methods: This cohort study used a prospectively collected registry of patients managed at a tertiary children's hospital. Multivariate logistic regression models were used to evaluate the relationship between first aid and the requirement for skin grafting. Secondary outcomes included time to re-epithelialization, wound depth, hospital admission and length of stay, and operating room interventions. Adequate first aid was defined as 20 minutes of cool running water within 3 hours of injury. Results: In our cohort of 2,495 children, 2,259 (90.6%) received first aid involving running water, but only 1,780 (71.3%) were given the adequate duration. A total of 236 children (9.5%) required grafting. The odds of grafting were decreased in the adequate first aid group (odds ratio [OR] 0.6; 95% confidence interval [CI] 0.4 to 0.8). The provision of adequate running water was further associated with reductions in full-thickness depth (OR 0.4; 95% CI 0.2 to 0.6), hospital admission (OR 0.7; 95% CI 0.3 to 0.9), and operating room interventions (OR 0.7; 95% CI 0.5 to 0.9), but not hospital length of stay (hazard ratio=0.9; 95% CI 0.7 to 1.2; P=.48). Conclusion: Burn severity and clinical outcomes improved with the administration of cool running water. Adequate first aid must be prioritized by out-of-hospital and emergency medical services in the preliminary management of pediatric burns.