You can safely drink about 1 liter (approximately 34 ounces) of water per hour because healthy kidneys can process roughly this amount of fluid in that time frame. Consuming more than 1 liter per hour over several hours can overwhelm the kidneys, dilute blood sodium levels, and lead to a dangerous condition called water intoxication or hyponatremia

. Water intoxication causes water to move into cells, including brain cells, potentially causing swelling and symptoms such as headache, nausea, fatigue, confusion, muscle cramps, and in severe cases, seizures or death

. For example, drinking nearly two gallons (about 7.5 liters) in two hours has been fatal in rare cases

. Therefore, while there is no exact maximum amount universally, a good guideline is not to exceed about 1 liter per hour to avoid health risks. Daily water needs vary widely depending on factors like age, activity level, climate, and health status, but an average adult typically requires around 1.5 to 3.7 liters per day from all sources

. In summary:

• Kidneys can process about 0.8 to 1 liter of water per hour safely.
• Drinking more than this amount per hour for extended periods risks water intoxication.
• Symptoms of overhydration include headache, nausea, confusion, and muscle weakness.
• Daily water intake recommendations vary but usually fall between 1.5 to 3.7 liters total.

Drink according to thirst and avoid excessive rapid consumption to stay safe