A firefighter loses 4 pounds (1.8 kg) during a training session. At least how much fluid should they drink to replace the fluid lost as sweat?

To determine the amount of fluid a firefighter needs to drink to replace lost fluids, it's helpful to consider the relationship between weight loss and fluid replacement. A general guideline for fluid replacement is that for every pound lost during exercise, individuals should drink approximately 16 to 24 fluid ounces of water.

In this case, the firefighter loses 4 pounds, which would suggest a fluid replacement requirement of between 64 to 96 fluid ounces (which is equivalent to about 1.89 to 2.84 liters). However, when evaluating the options provided, the choice of 45 fluid ounces aligns with a lower estimation of appropriate rehydration needs based on the guidelines, reflecting that not all fluid lost needs to be immediately replaced due to factors like thirst awareness and hydration levels when beginning the session.

This option is therefore the most conservative and practical choice for initial rehydration after a training session, especially in physically demanding environments like firefighting. This fluid intake can later be adjusted based on the firefighter’s individual needs, the environment, and ongoing hydration monitoring throughout their shift.