When it's well below freezing, is it best to cover your outside faucets with those styrofoam covers or to let them drip? (I live in South Texas, and our high today and yesterday has been in the 20s--very rare here.) I covered our faucets, but I can't drip them and leave the covers on. I checked one today, and it's frozen. So I wonder whether dripping or covering is more important in preventing burst pipes. Thanks.