In reply to Marek:
> I sometimes think that there's some 'hysteresis' in extremity circulation.
That certainly seems to be the case for Raynauds (which I have). Once your hands/feet go white, your core temperature can rise so that you are sweating, before circulation returns. Most of the time, I don't get hot aches as a result. One the rare occasion I have had hot aches, it's because I've got cold 'normally'. One particularly memorable occasion was walking up Sgorr nam Fiannaidh on a bitterly cold and windy day, stopping briefly at the top to have a bite to eat and take a couple of photos, and then realising I was very cold, and running along the ridge, to try to warm up, to the top of the Clachaig Gully, where I collapsed into a gurning heap, fortunately, in the sun and out of the wind, until the hot aches passed. And then came down via Cnap Glas, glowing nicely.
I'm crap at noticing I am cold (or I have a high tolerance to core temperature range). WFH during lockdown, I have sat at my computer for long spells, in my not very warm house, and got quite cold. I have had more chilblains than usual as a result, even quite late into the year. I have wondered if this is something to do with cycling every day to school/work, lightly dressed, and relying on the effort to balance the heat loss. Provided I am working hard enough, my skin temperature can drop quite low, whilst still having a sweaty back. I cycled to an ECG once, and the nurse applying the electrode patches was a bit concerned about how cold my chest was...
The point of this rambling is that I think there is quite a large variation in body reaction to cold...