Dry, thirsty air evaporates moisture from your skin, a cooling process that makey you feel chilly. But, with the humidity raised to recommended levels, you can dial your thermostat down to 68F and still feel comfortable. Heated air dries out wood framing around doors and windows, too. Shrinkage of the wood occurs, leaving spaces that permit cold, outside air to infiltrate the home, lowering the inside temperature and requiring more heating. Proper humidity reduces annoying wintertime static electricity shocks, too.