Quick update on water cooling after flare-up. I did my standard 30 minutes on a cross trainer then put my feet in luke-warm water (just below body temperature) for 15-20 mins. This had no significant affect on the flare-up disappearing, it was more or less the same as putting feet up and waiting 10-20 mins for it to calm down again.

Not sure how useful this would be for a diagnosis, but I'll report it to the specialist when I next see him after this bone scan next week.