Myth 6: You are already dehydrated when you feel thirsty.
That is not necessarily true. Dehydration is generally defined as a condition in which the concentration of substances in the blood has risen by 5% or more.
You will feel thirsty when the concentration has increased by 2%. So don’t panic if you are feeling thirsty and water is not readily available. You still have time to purify water and quench your thirst.