.....I noticed that places like Amazon are taking the temperature of their workers before allowing them into work. While that seems good in principal, we need to remember that a good 20%(?) of people infected will show no symptoms and yet be capable of spreading it. So, a temperature check will give a false sense of security.
This is not an all or nothing deal where if you can't get a 100% accurate test you just give up. I say the temperature check will get it right 80% of the time whereas you are saying it is wrong 20% of the time. If you combine masks, social distancing and the temperature test you will prevent, IMHO most (but not all) of person to person transmission.
It's the best that can be done quickly today.
Maybe tomorrow there will be another quick and dirty test that can be used that in conjuction with the temperature test will chip away at the problem.
For example there is a syndrome (that I personally know of someone who had it) called CORVID toes appear in COVID-19 patients who don’t exhibit any other symptoms. The toes get really ugly and very painful with red, purple and/or bluish lesions. If you ever have seen anyone who had shingles, they looked ( and hurt) like that.
There is also loss of smell and taste in infected people as an initial symptom (before fever).
We have to chip away at this thing until better treatments and perhaps an early vaccine happens.
IMHO, don't underestimate the benefit of having a lot of really smart people working on the problem.