What is the most appropriate management for a three-year-old boy with a painful, swollen wrist?

Applying a rigid splint in the position found and securing the limb to the boy's body is the most appropriate management for a three-year-old boy with a painful, swollen wrist. In cases of suspected fractures or injuries, immobilization is crucial to prevent further damage and alleviate pain. By applying a rigid splint, you provide stability to the injured area, which is especially important for a child who may be moving unpredictably.

Securing the limb to the body helps in minimizing movement, reducing pain, and keeping the injury stable until further medical evaluation can be performed. This approach not only addresses immediate concerns but also prepares the child for safe transport to a medical facility for further assessment and treatment. Proper immobilization is a foundational concept in first aid for managing musculoskeletal injuries effectively.