What ones were they krich? If it was some of your tropicals and it was only a few nights then they should still be okay. They will lose there leaves because of it so just bring them in and cut back the watering till new leaves start to pop but the tree itself should still be fine. I actually like to leave my tropicals out until right after the first frost. I feel it helps to make the tree itself more hardy. Mine have only been inside now for about 2 -2 1/3 weeks now.