The recent arctic vortex has made it difficult to stay warm, even when you're indoors. A few of you have written to ask about indoor plants that aren't enjoying the chill. If you can't give them enough heat, try making up for it with a little extra humidity. Cluster the plants together, place a tray of water nearby and/or cover them loosely with plastic. They should be able to survive a few more frosty morning.
It's hard to believe, I know, but some plants prefer cool temperatures. Even many of the plants that thrive in summer's heat need cooler temperatures in the winter, when they are taking a well deserved rest. Tender plants like this Flowering Maple, Angel's Trumpet, Meyer's Lemon and Gardenias, don't go completely dormant, when you bring them indoors, they just slow down. They still need plenty of light and regular water, but they do best with a little chilling, maybe 45 - 50 F. (7 - 10 C). It's on the cool side for us, but the plants love it. Here's some more info and a list of plants that want to chill out.