Installing a humidifier in a baby's room is practically a rite of passage for parents. When your baby has a cold, one of the best things you can do to keep her comfortable is to make the air she breathes is moist by using a humidifier. Moist air keeps mucus more liquid, which prevents stuffiness, making it easier for baby to breathe. The question is, which is better: cool mist or warm steam?

Both are equally effective at putting moisture into the air. But these days most pediatricians recommend the cool-mist option for the simple reason that there is no danger of burns from accidentally spilled hot water or from the steam. There is one drawback to the cool-mist machines, though: Since the water isn't boiled, the machines are an ideal breeding ground for bacteria and mold. Since breathing either could irritate your baby's lungs -- particularly worrisome for children with asthma and other chronic respiratory problems -- you must be diligent about following the manufacturer's cleaning instructions. That means scrubbing the machine daily with soap and water, vinegar, hydrogen peroxide or bleach (whatever the manufacturer of your machine suggests).

If possible, fill the machine with water that has a low mineral content, either distilled or filtered water (e.g., tap water that you've run through a filter, such as a Brita or Pur), since the minerals can build up on the machine which then disperses them into the air, potentially irritating the lungs of sensitive children. Place the humidifier about three feet from your baby's crib, but not so close that she could reach out and touch it or knock it over.

If you live in a part of the country where the air is very dry during winter, you might consider running a humidifier at night when your baby isn't sick to keep nasal passages from becoming dry. Just be sure that her room doesn't get so humid that water condenses on the windows, pictures, or walls. When a room is too humid, bacteria and mold thrive on furniture, walls, carpet, drapes and bedding.


Nevada-based freelance writer Dana Sullivan is a frequent contributor to Your Baby Today and also writes for Fit Pregnancy and Parenting. She's mom to Liam, 4, and Julia, 2.