Being 72 myself, I am obviously concerned. But one thing for sure, it is not the common cold.
If behind a paywall, the gist is that if the virus manages to get into the lungs things can go from mild to moderate to critical in very short order. The “tipping point” can be a matter of a day or so in older or compromised people.
It can damage the mucus membranes and cilia that keeps lungs clear in healthy individuals. Then other pathogens that flourish in our bodies can follow into the upper and lower respiratory systems.
Lack of oxygen to the other critical organs such as kidneys, liver and heart is the lethal part.
Don’s oxygen concentrator was probably a wise purchase.
Looks to be a great day in the neighborhood. Washing your hands often and picking your nose less should help.