We have a 6 hour layover at Heathrow, flying from Milan to Seattle. We will have our PCR test results to board in Milan, but British Air told us that we will need to test again during our layover (we're assuming on site).
Has anyone had this experience while laying over at Heathrow? Did you test in the terminal? Did you do a PCR test 48 hours prior to departing another European city (twice)?