Hi Gerry. I'm thinking he's got a Tropical Hibiscus, H. rosa-sinensis. The main thing is to keep it from freezing. If he has a nice sunny south facing window he can keep it near that making sure there is not a lot of cold air coming through the window or getting hit directly by a heat from a register. Also don't water as often, and keep the soil on the dry side of moist. If the leaves start to brown on the edges it's probably wanting more humidity so one good misting once a day. Also don't be surprised if some of the leaves start turning yellow and fall off.