When you’re Fresh, you’re +1D to all tests. But once you gain a condition–even if you alleviate it immediately, like by drinking from your water skin–you lose the Fresh condition. And Fresh can’t be regained until you return to town (and only then if you successfully jump through some hoops).
OK, I understand that. I was looking at it from the angle that Fresh is a Condition like any other so gives you the bonus when you have it and when the GM tells you you’re no longer Fresh you un-check it and therefore no longer have the bonus, i.e. no need to explicitly state when the Fresh Condition is lost.
Maybe “+1D to all tests. Lost when another Condition gained.” would be clearer?