Speaking of, can someone explain why the TSA security theater does not include body temperature measurement (or any other screening for COVID symptoms) nowadays

Speaking of, can someone explain why the TSA security theater does not include body temperature measurement (or any other screening for COVID symptoms) nowadays? The whole airport situation is weird: mask enforcement in the environment where people can plausibly socially distance (airport terminal) is hardcore, yet when they are stuffed into a plane like sardines for hours without any distancing they can take the masks off to drink or eat. Or even sneeze, as the case may be. And _nobody_ screens for even the most obvious symptoms of infection. You can sneeze and cough your way straight to the plane flying a domestic flight, and infect everyone inside if you wanted to. They should run a "red team" to show that.