Anaemia and hyperhydrosis can be ruled out. In fact, I sweat very little, which some say is a sign of other issues.
Raynauds is IMHO a bit of a bogus catch-all. My guess is that Raynauds is mostly a stress induced Hypothalmic condition in most cases... I know that in my case, stress does bring on the temp drop...but of course whether it is mental stress or the stress of facing 50 below..the organism probably reacts in somewhat the same fashion.