Mist Humidifier is going to put more moisture into the air. The thing to remember is that wherever there's water, there is also mold, spores, and bacteria. The lower the temperature, the less mold, spores and bacteria. This is enough reason for most pediatricians to recommend cool mist instead of warm. Cool is generally safer than warm (or hot) as well. You can always ask the your PD about the issue, i think that most PD will suggest getting a cool mist humidifier as well.