Well, on the ground at the gate, it should have been blowing cool air if the plane was connected to the ground air conditioning at MFE. That's assuming MFE has ground air conditioning units, but I'd be really shocked if they didn't.

In any case, I know that it was quite uncomfortable. I managed to fly twice during the month of June on a Chautauqua-operated Continental Express CRJ (the same plane both flights) that had barely functioning air conditioning, which meant that while the air was blowing and cool while at the gate, after push-back it was very warm by the time we took off, and it didn't cool off much at altitude. Fortunately I flew that particular aircraft again last week, and the air conditioning was working again. But I wonder how many flights it went out on with broken air conditioning.