Skin color would be a good indicator...
The skill he needs to work on is his reflexes.
Depending on how much is taken and the physical condition of the individual, alcohol can cause:
<span>Slurred speech; Drowsiness; Vomiting; Diarrhea; Upset stomach; Headaches; Breathing difficulties; Distorted vision and hearing; Impaired judgment; Decreased perception and coordination; Unconsciousness; Anemia (loss of red blood cells); Coma; and <span>Blackouts (memory lapses, where the drinker cannot remember events that occurred while under the influence)</span></span>
