SciLights: Flu and the Desert Air
Why does flu season tend to occur in the winter? You may want to ask your guinea pig.
Your mother always told you that you’d “catch your death of cold” if you went outside without a hat, but science has come to the rescue. Some old and new research suggests that it’s the dry winter air that’s actually at fault.
Picture this: you take one guinea pig, and infect it with flu virus. Then, you put him in a cage next to a healthy guinea pig and see if he gets sick. Now change the temperature and humidity and repeat the experiment.
With enough trials, you will discover that the low humidity increases the rate of influenza infection. Good for you! (Bad for the guinea pigs).
It’s not exactly clear how this happens, but there is some suggestion that water droplets breathed out by the infected pig evaporate quickly so the virus can stay airborne longer. That gives it time to find the neighbor pig and set up shop.
Some of the more recent literature argues that it’s absolute rather than relative humidity that makes the difference, but we’ll leave that to future studies.
Why should you care?
The point of talking about this topic on an eco-blog is that you have control over your home’s humidity, and therefore, your chances of spreading the flu!
Air outside your house is cold in the winter, and cold air can’t hold much moisture. When it comes inside through the door or air-leaks you haven’t had the chance to seal, it warms up, and warmer air can hold more water. In other words, that warmed-up air gets even dryer.
With its greater capacity to hold water, the warm air sucks moisture out of everything it touches, leaving chapped lips, chapped hands, and airborne flu viruses.
What you can do
First, seal the air leaks around windows, doors, and any other place you can feel a draft. As you breathe, you add moisture to the air, and the house is designed to circulate that warm, moist air around. Letting in cold, dry air through leaks will make your house dryer than the desert and not nearly as warm!
Second, you can add more moisture. I keep plants that will respire and add water to the air through their leaves. But if your furnace has a humidifier, use it, or get a standalone unit. Just be careful, because some warm-mist humidifiers eat a lot of power.
You’re aiming for a relative humidity between 30 and 50%, which will make you feel warmer, save your dry skin, and hopefully keep you from catching what the guinea pig has.
Related posts:




