What is the appropriate procedure for managing a head injury sustained in water?

Stabilizing the head and neck while avoiding unnecessary movement of the victim is the appropriate procedure for managing a head injury sustained in water. This approach is crucial because any movement can exacerbate potential spinal injuries that may accompany the head injury. When a head injury occurs, there’s a risk of damage to the cervical spine, so maintaining the victim's position is key to preventing further harm.

In a water scenario, where movement might be more challenging and risky, keeping the head and neck stabilized is even more critical. This not only helps protect the spine but also ensures the airway remains unobstructed and minimizes the risk of drowning if the victim is unconscious.

The other options include actions that could lead to further injury or complications. For instance, calling for emergency assistance but leaving the victim alone could result in deteriorating conditions without immediate support. Immediately removing the victim from the water without proper stabilization could worsen potential neck or spinal injuries. Conducting a head-to-toe assessment before stabilization might delay essential care and unnecessarily risk further injury. Thus, prioritizing head and neck stabilization is essential for ensuring the best possible outcome in such emergencies.