Hi Dave,
Like you I was diagnosed only a few months ago and am on Gliclazide and Metformin (Ramipril and Aspirin too).
I suffered from cold feet and hot body long before diagnosis and suspect it was an early warning sign that was ignored. I was on business in the dusty heat of Cairo when it first became apparent that my feet were still cold!
After diagnosis I was wondering if this was the start of peripheral neuropathy? Although as it is most noticable when lying down or with the feet up, I reckon some sort of diabetic circulation problem is more likely (although my blood pressure has always been high).
I have another theory though, based on the body's automatic 'survival mode'.
We rightly monitor and control BG levels as these cause the long term damage, but the lack of insulin (or effective insulin) can become a threat to the well being of the body in the shorter term - no insulin = no energy available = problems for heart, brain, breathing etc.
I can not believe that the body does not have a self protecting mechanism where the depleting levels of insulin (or effective insulin) are reserved for the brain and critical organs. You become tired so the last useful insulin is not wasted on physical activity but is available to keep vital organs functioning.
I know this tiredness was for me more than just sleepiness, it was a lethargy that completeley de-motivates you from doing even things you enjoy, which can only be the body protecting the vital functions by limiting activity. I'd say that even higher mental functions get impaired as the brain has to use all available energy for the autonomus functions like breathing etc.
The same can probably be said for the circulation and body temperature control around peripheral areas - your heart, lungs, liver, kidneys and head will always be warm, hand, feet, legs and arms can all be de-emphasised in survival mode.
It's just a theory, but for me the sudden on-set of the tiredness was almost as if a threshold had been exceeded and the body was shutting down to preserve itself. Shame it doesn't switch back as quickly
My feet are still cold after nearly three months of medication and a month of better BG control, but the tiredness is finally a little less and the 'fog' around those higher brain functions is clearing, so I remain hopeful of having warm feet again soon