Dr. Bill,

I have been experiencing this too.  I am also finding myself much feeling colder than usual this year--ie. my hands and feet are like ice, not just subjectively, but if someone else touches them. Sometimes the rest of me is very cold at the surface, even when I am warmly dressed.

My guess is that constriction of the blood vessels is causing slower absorption of insulin.  I had a dramatic occurance last week where my blood sugar was surprisingly high 90 minutes after using a standard fast acting dose for a known meal.  I took a hot shower that lasted about ten minues and tested again. My blood sugar dropped 80 mg/dl after the hot shower! 

Since the insulin I use  (Apidra) usually peaks at 1 hour  (along with the food), this was very interesting.

I inject in my thigh because I bruise very badly in the tummy area, but I am thinking that this might not work as well in winter.

i am currently taking metformin and every year around daylight savings time i need to reduce my dosage to 500mg in the am and 500 in the pm. and on more active days only 500 in the am is fine. but around october i need to take 1000 in the am as well as 1000 in the pm... iam interrested in learning more about this "seasonal glucose levels"