Originally Posted by Xyzzy

I've been through a few countries where medical teams use infrared cameras to scan all passengers for fever. While I've never seen that in the US, it certainly could happen here.

Furthermore, traveling while sick exposes others to whatever it is you have. As a matter of public health, you could be detained, quarantined, fined, etc. The decent and polite thing to do (not to mention the smart thing to do for yourself) is to NOT travel with a high fever. I don't want t get sick, and neither does anyone else.