Which of the following is NOT a symptom of a casualty in shock?

A calm demeanor is not typically associated with a person experiencing shock. Individuals in shock often exhibit various signs of distress or confusion due to the body's response to life-threatening conditions, such as a severe injury or significant blood loss. Shock triggers a physiological response that can lead to increased heart rate, anxiety, restlessness, or agitation as the body tries to cope with decreased blood flow and oxygen to vital organs.

In contrast, clammy skin, pale skin, and restlessness are common symptoms of shock. Clammy skin results from the body diverting blood to essential organs, leaving less blood flow to the skin, while pale skin can indicate reduced circulation. Restlessness, as a symptom, reflects the body's stress response, where the person may feel anxious or agitated due to the underlying trauma or lack of adequate blood supply to the brain. These combined factors make it clear why a calm demeanor stands out as NOT being a symptom in this context.