Advice on buying my first wearable device
I'm interested in buying my first wearable device, a smartwatch, fitness tracker, or smart ring. There have been a number of articles about how these wearable devices can warn of cold, flu, and even COVID-19 several days before the symptoms begin. If I see those first warning signs (and cannot point to a change in routine or other clear explanation), then I can take some pre-emptive actions, like getting tested, scaling back activities, masking up more vigorously, sleeping more than usual, and eating lots of garlic and ginger. I can avoid spreading viruses and maybe even avert all symptoms as well.
From what I've read, the relevant parameters that can be monitored include resting heart rate, heart rate variability, skin temperature, electrodermal activity, and blood oxygen. Blood pressure monitoring would be nice. (Should I get the blood pressure monitoring feature? Or is is too expensive/inaccurate to be worth it?)
I should note that I'm NOT concerned about my step count or how many calories I'm burning. I know if I'm getting enough exercise, and I'm too skinny to be concerned about calories. I use Cronometer just for making very sporadic spot checks of my diet, and I'm more interested in my vitamin/mineral/fiber intake than my calories and macros.
I'm not interested in buying an Apple or Microsoft product. The Apple and Microsoft ecosystems are too expensive for me.
What features should I look for in a wearable device?
Let me know what you think of the low-end wearables available at stores near me: