After being told to be at the airport 3 hours before an international filght, we got there in plenty of time only to find out that the carrier (British Airways) doesn't open their service area until two hours before the flight. We traveled on an incredibly busy day (the morning after the solar eclipse in Iceland) and the entire airport was jammed. Only two stations for British Airways were open to process passengers, and those of us traveling economy were made to wait until almost all premium passengers were processed. There was no method to self check in. Consequently we were processed with almost inadequate time to go through security and passport control to board our initial flight. However, once on board all was good. It's odd, I booked premium ecocmy tickets for myself and my husband, but we had economy seats for the first leg of our journey, although premium economy seats were available on that flight. When making this reservation through Kayak, I chose a trip that included a 1.5 hour layover at Heathrow Airport, assuming that the service (Kayak) would offer flights that allowed sufficient time to transfer between them. I was wrong. We had to transfer terminals that included a train between terminals and additional security, and only made out connection because we requested wheelchair service for my husband who has neuropathy in his feet due to chemo. Had we not requested that service, we would have missed our connection totally. Kayak really should inform passengers that they need at least two hours between legs when flying into large international airports, if not three or four hours .