If the soil has fallen away from the root system as opposed to being carefully dug and balled, the chances of it surviving are slim.  Even if it was carefully dug and balled while it was actively growing in mid-summer, the shock would probably kill it.  The best you can do is keep it in the shade and keep it moist.  You could also spray it with Wilt-Stop, a substance that prevents some moisture loss through the leaves.   Good luck.