What action should be taken when a firefighter shows signs of heat exhaustion?

When a firefighter shows signs of heat exhaustion, the best action to take is to administer cool water while avoiding electrolytes or sugar. This approach is correct because the primary goal is to lower the firefighter's body temperature and rehydrate them. Cool water helps to dissipate heat effectively, and it is crucial not to overwhelm the body with sugar or electrolytes, which may complicate rehydration processes.

Administering caffeinated beverages would not be appropriate since caffeine can further dehydrate the individual and may exacerbate the symptoms of heat exhaustion. Encouraging vigorous exercise is counterproductive in this situation, as the firefighter is already experiencing distress due to elevated body temperature and fatigue. Wrapping a firefighter in wet blankets could potentially lead to additional complications, including causing the body to retain heat instead of allowing it to cool down effectively. Therefore, providing cool water without added sugars or electrolytes is the most suitable and effective response during instances of heat exhaustion.