Which of the following is NOT a sign of dehydration?

Fatigue is not commonly recognized as a direct sign of dehydration. It is noteworthy that while fatigue can occur as a consequence of dehydration, it is not a distinct or primary indicator. Dehydration primarily manifests through physiological markers such as thirst, which is the body's way of signaling the need for fluid intake, and dry mouth, indicating a lack of saliva due to insufficient fluid levels. Excessive sweating can also lead to dehydration, as it can cause a significant loss of fluids and electrolytes. Therefore, while fatigue is a potential symptom that may arise from various causes, it does not specifically denote dehydration in the same way that the other options do.