Man, it's a shame those companies are the only way we can get water. People who drink too much water are completely in their pockets 😔

Its not actually a reliable indicator in the elderly body. And aspiring endurance athletes, recreational runners and cyclists, or those that work outside in the heat need to preempt that shit. They should be drinking water, and electrolytes on longer bouts. You lose 0.5-1.5 liters of water per hour from sweat, and thirst can lag. You can become dehydrated before you even realize, and it can take a long time (up to 24 hours) to get back to normal levels.

Sedentary in a climate controlled room, sure, drink when you're thirsty, I don't care.