It may well be the other way around- if your electrolytes are out of whack, this can cause unquenchable thirst. Use extra salt, particularly sea salt which has potassium and magnesium in it. If you can get hold of some magnesium and potassium supplements, do so, but definitely eat more salt.
If your legs start to cramp up and you get headaches, fatigue and unquenchable thirst, this can be severe dehydration and will not be cured by drinking water alone, you must replace electrolytes. I had these symptoms once on a long flight back from India, but couldn't remember the quantities of sugar and salt needed to replace electrolytes. I drank and drank water with no effect on my thirst. Had to wait to get to Heathrow and buy some Diarolyte! Spent most of the flight passed out. Not the best time of my life.
A lot of the above symptoms are similar (and related) to "carb flu", but having experienced both, the signs of electrolyte depletion/dehydration are more severe than carb flu. The leg cramping with dehydration was MUCH worse, as was the thirst. If you get severe symptoms I wouldn't mess around- replace the electrolytes even if it means putting sugar in your system.
Sorry, that all sounds a bit scary. It's just that the words "unquenchable thirst" ring electrolyte alarm bells.