In reply to FrankBooth:
Hi Frank, What course are you running? I've always tended to take a variety of items to basecamp and then make final decisions based on prevailing conditions. The rules on clothing are quite ambiguous, specifying a "Warm layer" has always struck me as being an extra top over and above the base layer you'll be running in. My setup has varied from Lighweight micro fleece to down vest.
It's more about what your comfortable to be "Getting away with" than anything else.
Cheers
Jim