Hydration plays a critical role in regulating body temperature by maintaining the body’s fluid balance, which is essential during physical activity. Adequate hydration aids in cooling the body through perspiration. When the body overheats, sweat evaporates from the skin, dissipating heat. Insufficient hydration can inhibit this process, leading to overheating and reduced performance. Furthermore, dehydration can affect cardiovascular function and increase fatigue, emphasizing the need for athletes and active individuals to stay well-hydrated.