https://multiple-sclerosis-research.org/2020/04/mscovid19-pulse-oximetry/ - "If you are single I suggest going to extraordinary lengths to protect yourself if you have to self-isolate with COVID-19. You may have heard about the tragic death of a young surgical trainee who died alone at home from COVID-19 in Belfast last week. He probably died from pulmonary complications of COVID-19 that had gradually crept up on him and by the time he needed hospitalisation and ventilatory support he was probably too unwell to do anything about it. A big issue is that as you become hypoxic (lack of oxygen) your thought processes become clouded and your ability to make a judgement about your own health become erratic." - These are between £25-£35 on Amazon. - https://smile.amazon.co.uk/JZK-301-Precision-Finger-Oximeter-Monitor/dp/B0875GSQLF/ref=sr_1_1?dchild=1&keywords=pulse+oximeter&qid=1588155408&s=books&sr=1-1