You hear it all the time, but it is a "must" to carry water with you everywhere all day. Small sips will decrease the effects of the air pollution. You might need larger gulps for the dehydration. Do not leave your room without a bottle of water.

I like the Financial District location of the Westin as being clean and safe. You will probably take the taxi anyway. It is only a 10-minute or less ride to the Forbidden City/Tian'an Men area.