Story: in colonial times the british used to die of heat stroke, the indians didn't. They found out it was because the indians put salt into their lime juice and the british rulers used sugar. Moral: if you're sweating loads, don't go too crazy on cutting back on salt, as you lose a lot when you sweat. That's why energy drinks contain sodium and chloride.
If you don't eat salty things like chips, salted fries, etc. I would not worry about it. Some people sweat more than others, I myself sweat like a pig during workouts.