Drinking hot water burns virtually no calories—the thermogenic effect of consuming water is negligible and roughly the same whether the water is hot or cold. Your body does expend a small amount of energy to warm cold water to body temperature (estimated at 2–3 calories per liter), but this minimal cost disappears entirely with hot water since no heating is required. The popular claim that hot water "boosts metabolism" or causes significant calorie burn is a misconception. While staying hydrated supports overall metabolic function, the act of drinking water—hot or cold—is not an effective weight loss strategy. The calorie expenditure from digestion and processing water is negligible compared to the energy burned through daily activities, exercise, and basal metabolism. If you're interested in hydration and health, focus on drinking enough water overall rather than its temperature, as both hot and cold water provide the same hydration benefits.