Which of the following is NOT a symptom of carbon monoxide poisoning?

Extreme fatigue is not commonly recognized as a classic symptom of carbon monoxide poisoning. Instead, more typical symptoms include headaches, nausea, dizziness, weakness, and irritation of the eyes. These symptoms result from the body's reaction to carbon monoxide, which interferes with the oxygen-carrying capacity of hemoglobin in the blood, leading to a lack of oxygen in vital tissues.

Though fatigue might occur as a secondary effect due to lack of oxygen or from the body's response to toxic exposure, it is not the most immediate or recognizable symptom when identifying carbon monoxide poisoning. Recognizing the primary symptoms is crucial for timely intervention and the safety of individuals potentially exposed to carbon monoxide in a boating context or any enclosed space where exhaust fumes can accumulate.