Warm up area

[Manny A]

You'll find your answer in NFHS Case Play 1.7.3 Situation B:

"While the game is in progress, the umpire notices that a non-adult is warming up the pitcher, but is not wearing an approved helmet and mask combination and throat protector (a) within the confines of the field, or (b) outside the confines of the field.

"RULING: In (a), the umpire shall warn the pitcher's head coach of the infraction and prohibit the pitcher from warming up with that individual until the non-adult secures the proper equipment. The next player not properly equipped will result in the player and the head coach being restricted to the dugout/bench for the duration of the game. In (b), rules prohibit team personnel from being outside the confines of the playing area or designated warm-up areas during a contest. The umpire shall warn the head coach of this infraction. The next offender is restricted to the dugout/bench for the duration of the game. The umpire's jurisdiction is restricted to the confines of the field and designated warm-up areas. (3-5-1; 3-6-1; 3-6-6)"

So a team cannot have a designated warm up area outside the confines of the field.