I need oxygen during the flight and this was provided free of charge by Thomson Airways. I had to pre-book that when we booked the holiday. This was just a phone call, then I had to get my GP to sign a letter to say that I was fit to fly and needed oxygen during the flight. That had to be done no more than four weeks prior to the flight. I have my own portable concentrator for use while I am abroad but found the airline service a real help as the flight is four hours which means my batteries are running very low, if not actually run out, if used from home to cruise ship. The cabin crew on the plane were really helpful and caring - they kept checking that I was OK. With this support I was able to enjoy a week in the sun in January and here I am in Agadir, with my Airsep Freestyle.
Have O² will travel !!