The difference between warm- and cool-mist humidifiers, according to the Mayo Clinic, is merely the humidifiers' temperatures. Warm mist humidifiers heat water until it steams, and cool mist humidifiers create a vapor. Both produce equal amounts of humidity, however.
Although both warm- and cool-mist humidifiers accomplish more or less the same thing, people with breathing ailments, such as asthma, may find cool-mist humidifiers easier on their lungs. The Mayo Clinic also cautions against using warm-mist humidifiers while small children are around for safety reasons. Aside from functionality, cool-mist humidifiers are less expensive than warm-mist ones. They also require less cleaning than warm-mist humidifiers, which are more prone to bacterial growth, although it is recommended that you clean both types of humidifiers daily with nine parts of water to one part bleach. Aside from distributing vapor medications, humidifiers are good for those who suffer from allergies and sinus problems. They're also efficient at deterring common conditions such as chapped lips and dry skin, which are sometimes caused by dry air. Healthy humidity levels are between 35 and 50 percent. If your house or office is too dry, it is recommended that a humidifier is used to add moisture to the air.