full of furniture, books, plants, media and treadmill had me wondering on the quality of air when patio door is closed.

Last winter I often woke wanting more sleep and lethargic with it.

To my knowledge there is no gadget to measure the level of CO2 in the air – which I thought would be higher being in a closed environment.

However, there is this gadget to measure the levels of oxygen in the blood which I bought and monitor. The higher (97) the better down to not so good (93 or less).

 

This leads me to wonder how using masks lower the oxygen level in our blood? I am and will still wear a mask when outdoors. 82, triple vaxxed and waiting for next booster.

 

Thinking I might now lower the mask when on long walk and no-one else in sight.