Warm-mist vs. cool-mist humidifier: Which is better for a cold?

When should I use a cool-mist humidifier vs. a warm-mist humidifier for a child with a cold?

- Sue / New York

Mayo Clinic pediatrician Jay Hoecker, M.D., and colleagues answer select questions from readers.

Answer

For safety, always use cool-mist humidifiers with children. Hot water or steam from a warm-mist humidifier or steam vaporizer can burn a child if he or she gets too close.

Humidifiers add moisture to the air, which helps ease coughing and congestion due to a cold. Warm-mist and cool-mist humidifiers are equally effective in humidifying the air. Also, by the time the water vapor reaches your child's lower airways, it's the same temperature regardless of whether it started out warm or cool.

Another benefit of cool-mist humidifiers is cost. Cool-mist humidifiers are less expensive than warm-mist humidifiers because you're not paying for the heating element. If you use a humidifier, be sure to keep it clean to prevent the growth of bacteria and molds.