This is an important thing to note.

It's easy to avoid though. Simply put a few grains of salt into your water.

In the army, as a supply-core nco, that was a must, especially in the summer. A spoon of salt for every jug. I'm gonna refrain from putting the ratios here, because I don't want anyone to go necking salt because of me. Normally we get enough salt from food, so I'm afraid of some trendy would-be healthy kids starting to add a bunch of salt into their water bottles even when they don't do any sweating, thinking it's healthy for them.