You can use the water for washing, then drink it.
If you need this water to survive, then do not waste it for anything else.
If you do not need this water to keep hydrated, then yo must use it for washing.
However, if you do not have water with you, or need the water to stay hydrated, you must search or water, 18 min if it’s out of your way, 72 min if it is in your way.
If however you are sure that you will not find water, there is no need to wait.
Keep in mind, this is only bshas hadchak. I don’t think that you shoul go hiking and put yourself into a Bshas hadchak situation