I think extreme temperatures wll make you drink more often or suffer Thirsty. But also that is coming in the next book in all likelyhood since the Volcano God Horn is going to be a part of the next book.
Oh? Do you have any idea when this might be? I'm making a homebrew setting to go on FLW and my setting has a significant desert area as well as sea trade, so I'm looking to make rules for both of these settings.
Nope. The writer had mentioned that he was working on it before the Bitter Reach officially came out. I would expect a similar time table from the original release to Bitter Reach before we see Aslene.
That being said, look at bitter reach. The colder it is the more often you have to make an endurance roll or become cold. Instead the hotter it is the more often you have to make an endurance roll or become Thirsty. Which can be relieved by drinking water. Which will deplete their water supply faster. so on and so forth.