I'm the guy that needs to drink a liter of water a day to survive in a normal climate. Beijing has upped the ante and I need about two liters on average. Despite my water consumption, I wake up every morning super dry. In fact, I often dry out so much that I wake up a few times during the night just to chug water.
Some people say that a humidifier and an air purifier are necessary for life in Beijing. I've been able to make it this far without the better air pair, but I am easing in.
I didn't spring for an air purifier yet, but I picked up a cute, animal-shaped humidifier, and since then everything's been coming up Milhouse! I paid a little more than 10 USD for an awesome sheep-shaped super-sonic humidifier. I've only been using it for a week or so, but its really made a difference for me AND for Veronica.