I watched some information about reducing the impact of COVID-19 with suggestions to open your windows to let in fresh air, to put a fan in the window and blow out the stale air that accumulates when we have tight, well-insulated homes. Not bad ideas at all, no
matter whether there is a pandemic raging or not.
I have an additional idea: Why not bundle up. get outside an walk? That not only gives you fresh clean air to breathe, it expands your lungs, boost your immune system, gets more blood and oxygen circulating in your brain, and exposes you to beneficial microorganisms. What could be better?