To fight fatigue, a driver should do all of the following EXCEPT...

To effectively combat fatigue while driving, it is crucial to prioritize rest and sleep. Avoiding sleep, as suggested in the answer, is not a viable strategy; in fact, it exacerbates fatigue and significantly impairs a driver's ability to concentrate and make sound judgments on the road. Adequate sleep is essential for maintaining alertness and overall cognitive function while driving.

In contrast, all the other options are valid strategies for fighting fatigue. Avoiding heavy foods helps prevent sluggishness that can arise from digestion, while steering clear of excessively warm environments in the vehicle can prevent drowsiness caused by heat. Additionally, avoiding alcoholic beverages is vital since alcohol consumption leads to reduced alertness and can severely impair driving abilities. Prioritizing sufficient sleep remains the most important action a driver can take to ensure safety on the road.