Dehydration Limit

A creature can go without water for a limited number of hours before dehydration sets in, this is called their dehydration limit. A character's dehydration limit is equal to 24 + twice their Constitution modifier. After every 4 hour period beyond their dehydration limit, the character gains a level of exhaustion at the end of the fourth hour.

A normal day's worth of water consumption resets the count of hours without water.