How should you check for breathing on an unconscious casualty?

To check for breathing on an unconscious casualty, placing an ear over the mouth and nose is the most effective method. This technique allows you to directly monitor the casualty’s airflow, making it possible to hear any breaths they may take and feel the airflow against your ear. It provides a clear indication of whether the person is breathing or not, enabling you to assess their condition accurately and determine the next course of action.

Other methods, like looking at the face for color change, can provide some information about the casualty's circulation and oxygenation, but they do not directly assess breathing. Listening for heartbeats primarily checks for circulation rather than respiratory function. Observing limbs for movement is also not a reliable indicator of breathing, as an unconscious person may not exhibit noticeable movement despite having a pulse or even breathing. Thus, using the ear-over-mouth-and-nose method is the most reliable and immediate way to check for breathing.