There’s a Dr John Campbell that has a youtube channel and has been doing videos on coronavirus. He said when it’s cold, the blood flow to your nose/sinuses gets restricted and that makes your sinus system more susceptible to absorbing germs that you breathe in.
I found this especially interesting. Sleep is the best thing for an immune system.
I think we should start hand wash shaming people. Like fat shaming or smoker shaming. Hey you did not wash your hands. Go wash your hands. I do it with my family. Perhaps it’s the retired nurse in me.