George was an industrial worker who had just completed working four days of double shifts. At the end of his last 2 hours of the fourth shift he experienced an episode of dizziness and blurred vision. Describe what you think has happened to him and which systems are involved. What physiological factors account for the dizziness and blurred vision?

I am thinking either: Either a viral infection affecting the inner ear which throws off balance or Fatigue

Think four..... 16 hour days....One of your ideas has excellent validity. http://www.charminghealth.com/applicability/exhaustion.htm
However, You might also look at this site.
http://www.fred.net/slowup/habul44.html