Originally Posted by
windowontheAside
Yes, you can't reserve a treatment unless you are flying First. Gold status won't cut it I'm afraid.
however
BA.com says ". A complimentary 15 minute treatment menu is available if you are travelling in our First or Club World cabins or you are a Gold card member flying longhaul, when you use our lounges at London Heathrow and New York."
book on the day...