What is the recommended response for a casualty exhibiting difficulty breathing?

Administering oxygen is the recommended response for a casualty exhibiting difficulty breathing because it directly addresses the primary issue of insufficient oxygen in the bloodstream. This action can provide immediate relief and improve oxygenation, which is critical in emergency situations where a person's breathing is compromised.

In cases of respiratory distress, promoting oxygen flow can help stabilize the patient while further assessments or treatments are conducted. Providing supplemental oxygen can help alleviate symptoms and prevent further deterioration of the casualty's condition.

Other approaches, such as encouraging deep breathing exercises, may not be effective in acute situations where the person is struggling to breathe. Placing the casualty in a supine position could potentially exacerbate breathing difficulties, especially if they are experiencing conditions like choking or fluid in the lungs. Controlled evacuation may be necessary in certain scenarios, but it should follow immediate interventions that address the airway and breathing.