Fight Cold/Flu Season with Humidity

Goodness it's cold outside! In Chicago, on the first day of the year, the high was 1F, setting a new record for the coldest high temperature on the first day of the year, according to the Weather Service. Here's hoping it's warmer where you are.

In addition to the cold weather, it's cold (and flu) weather. There are flu outbreaks in 36 states, according to the CDC. One spot where cold weather and cold/flu season intersect is humidity.

Cold air can hold less water vapor than warm air. Ideal indoor humidity levels are between 30 and 50 percent. Too humid and you encourage mold and other allergens. Too dry and you dry out people's mucous membranes, leaving them more prone to catching a cold or the flu. Plus dry eyes, cracked lips, and headaches are likely. In addition, a study found that the relative humidity of a room had a direct impact on the infectivity of the flu virus. Within 15 minutes of being coughed into the air, the studied virus was still at least 70 percent infective in a room with 23 percent humidity. That infectivity at the 15 minute mark dropped to at most 22 percent in a room with 43 percent relative humidity. The researchers concluded that "maintaining indoor relative humidity >40% will significantly reduce the infectivity of aerosolized virus."

It is also vitally important that humidifiers be kept impeccably clean and well-maintained to avoid injecting bacteria into the air. 

Happy new year! Stay warm and healthy!

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