In emergency situations, what should you do if the casualty is unconscious and at risk of vomiting?

In emergency situations involving an unconscious casualty who is at risk of vomiting, turning their head to the side is the appropriate course of action. This position helps prevent aspiration, which could occur if the individual vomits while lying flat on their back. Aspiration can lead to serious complications, including choking or respiratory infection.

By positioning the casualty with their head turned to the side, any vomit can exit the mouth more easily, reducing the risk of it being inhaled into the lungs. This method is commonly recommended in first aid and emergency response protocols as a critical step to stabilize the person's condition and maintain their airway.

Other options do not adequately address the immediate risk of vomiting and the potential for airway obstruction. Keeping the person lying flat could increase the danger, applying cold compresses does not address the risk of choking, and giving water could lead to choking if the person is unconscious. Therefore, turning their head to the side is the most effective and safest measure in this situation.