[headstamp 2]

Sounds like something akin to Raynaud’s, Scleroderma, etc.

[mistfree]

Actually it sounds like PCH Paroxsymal Cold Hemoglobinuria
Found most often in children after a viral infection and the problem starts when the blood gets cool but doesn't actually manifest itself until the blood warms up again. Goes to the feet and hands, cools off and returns to the core and gets warm again. Or the so called ice cube test. Cool the spot then warm it back up. Self limiting disease goes away in time, but it can be very severe even fatal in some.