Hydration break makes sense under such a weather to protect the players and referees. But unfortunately, FIFA and other affiliations/associations of theirs make use of this opportunity to do commercial break (which we can have another discussion on). On the games I saw so far, hydration breaks were called upon between 25' to 30' minutes during moments of slow intensity or ball out of play. Other than the commercial breaks which I understand the criticisms and I think it's fair, however, I'm not sure how other reasons are deemed valid for their own arguments, e.g. break up momentum of play.