Every soldier must know how to identify and treat certain life-threatening medical conditions. On the battlefield, the ability to quickly evaluate a person's condition and to take immediate corrective measures can mean the difference between life and death. When treating a casualty, you must identify and treat the most serious condition first. In general, you must make sure that the casualty is breathing, then control any major bleeding, and then take measures to control shock.

During the evaluating or treating process, you should seek medical aid as soon as possible. Do not stop the treatment, but if the situation allows, send another person to find medical aid.

Your evaluation must be adjusted to the situation. If the environmental conditions favor heatstroke, for example, you will check the casualty's breathing, then quickly check for other conditions while you begin treatment for heatstroke. If a soldier collapses during a battle, however, you will probably spend a good deal more time looking for entry and exit wounds.

Some of the standard evaluation steps may be performed so fast that they appear to be skipped. A casualty who is yelling in pain, for example, is obviously conscious (responsive) and breathing.