Observation: I tend to get more done when I don't feel the need to wrap myself in something warm.

I should set up something to remind me ot log both values (warm clothes/blankets vs productivity) and see if this is really a thing, or if I'm simply not noticing exceptions.

I would assume there's a cause for this that won't be helped by making a conscious effort not to bundle up while trying to work (or at least, not much); circulation? Blood sugar? Blood pressure? Some other factor affecting body temperature (perceived or actual)? In which case, I'd clearly want to tackle that cause instead of blankets.