This device could save yr life:
The invisibility of COVID-19's 'happy hypoxia'
Some patients appear normal, yet their oxygen levels are 'seemingly incompatible with life.'
"Not sure how to detect an invisible oxygen deprivation? Luckily, a small over-the-counter device commonly found counter in pharmacies can help provide an answer at home. Place a pulse oximeter on your finger and it will measure and display your oxygen saturation and pulse rate within seconds."
https://www.healthing.ca/diseases-and-conditions/coronavirus/the-invisibility-of-covid-19s-happy-hypoxia
@AlphaCentauri
Great point!! ON it!