Yes, the indoor pool was heated during our end Nov-Dec cruise on the Bellissima around the Med. Hope you enjoy your cruise, it was also our first with MSC and we went in with low expectations given some of the reviews of MSC we'd seen. It turned out to be fabulous - ship was running nowhere near capacity, staff were wonderful, service was great and the food was fantastic. Thoroughly enjoyed, just a shame it was a little on the cold side!