Flying from PHX-ABQ on Sunday, boarding etc went fine, then we just sat there with the door open and no air going in PHX where it was like 100+ degrees. Finally the Capt. comes on and lets us know they reassigned the FO so we have to wait for another one, literally the FO got off the plane to go somewhere else. We ended up sitting there broiling for almost a hour, I really felt sorry for the peeps not in 1st class.