Mystery #4Tier 2thirst / brain / water balance
Why does your body make you feel thirsty at exactly the right time?
Your body somehow knows when to feel thirsty, usually well before you are in any real trouble. It is not just a dry mouth either: even with a perfectly wet mouth you can feel a deep need for a drink. How does your body know, from the inside, that it is running low on water?
Your guess
What do you think your body is checking to make you feel thirsty?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
Make a guess to unlock the hints and the answer.