The first thing I thought of when they started talking about those laser-style thermometers was… they’ll just load up on NSAIDS just before hitting the airport. That’ll lower a fever at least a degree or two… Be interesting to know if Duncan did that very thing.
Screening out the sick ones isn’t that important.
It’s the ones from day+1 to day+21 after infection that must be kept out. They won’t have a fever or feel sick.