They made you wear a dressing gown!
I didn't have to wear one at any stage of my medical. I would, howeve, advise wearing tracky bottoms and a loose shirt as you will need to be poked and prodded by the AME and for your ECG.
I would agree with the above, there's not alot you can do other than the following: -
1) Don't eat a packet of Sour Haribo before hand as that will **** up your blood sugar.
2) Don't drink at least 24 hours before hand.
3) If you smoke, don't stand outside the CAA HQ having a quick fag before you go in, they may frown on that!
3) Relax, the rubber glove is suprisingly friendly
CS