I wrote in my last post about an urgent care visit during a retreat. I used to get an annual sinus infection that was off the charts bad. Two things changed the equation: one: I got a humidifier. That improved, but did not solve things. Two: A shaman told me it had to do with some mold in an area where I sit outside. I used to sit on my step alot. A couple of years ago the eaves fell off during a storm. I haven’t had it since.
It turns out science supports the idea that humidity can prevent flu transmission when couples with keeping the heat at least around 68 degrees faranheit. At least with guinea pigs:
Figure 1 ~ Experimental Setup. Guinea pigs were housed in adjacent cages. Guinea pigs in cage 1 were infected by Palese with influenza. Palese observed how many guinea pigs in cage 2 became infected from the guinea pigs in cage 1 at different temperatures and levels of humidity. B, C) Transmission rates were 100% at low humidity, regardless of temperature. At high humidity, transmission occurred only at the lower temperature.
https://sitn.hms.harvard.edu/flash/2014/the-reason-for-the-season-why-flu-strikes-in-winter/