The fast gun like IR thermometers are not very accurate. And can be fooled. In one case an infected person took fever reducing medicine specifically so that they would be allowed on a plane where the temperature was checked on boarding.
My assumption would be that high accuracy solutions such as PCR testing or even the saliva testing that Paul is suggesting would be ideal, but potentially difficult to effectively rollout in a widespread manner. While IR thermometers are not very accurate, are they on a whole accurate enough to effectively screen out a sufficient number of people to reduce the R-factor viral spread below 1.0? Again, I’m not a medical professional, but shouldn’t we be biasing towards processes already being used by the multiple regions that have seemed to have successfully managed to reduce the viral spread below 1.0 first before seeking new solutions?