I was always a warm natured person and wore a long sleeved mans shirt for a jacket in the winter but not anymore. I now wear tights and long sleeved sweaters over a T shirt. My feet and hands are a lot colder. Doesn't matter if it is summer or winter for my feet. I wears sock and never sandals in the house. As you say, I am warmer if I am walking around. Poor circulation I think.

diabetes causes many different problems one is poor circulation it might be a good idea to address the diabetes than the symptoms. It has been known since 1958 that chromium supplements will prevent and treat diabetes.University of Vancouver, BC, Canada stated that vanadium will replace insulin for adult onset diabetics.
There is naturopathic doctor have been very successful in treating diabetes with diet and minerals.

Dr. Scholl's has a thing for your feet that warms them I think& massage. My folks have them but didn't use them ,dad just wore socks all yr long & had extra blanket over bottom part of bed to keep his feet & legs warm. That was all he needed. Too hard for them to use the foot heater as 91 & 96 & they could fall over it. Dad slept with his socks on all yr around until he passed away at almost 96(missed it by 8 days) Might want to keep fleece throw handy & throw it over your feet .when you sit down. Keep socks on in bed but change daily because if feet sweat might get infection.If you start getting bedsore on foot, keep it dry ,no lotions I found out from nurse & so kept dad free of bedsores.Also used piece of that foam rubber"bumpy mattress stuff so feet weren't flat on bed". Good Luck! The fleece throws are available almost everywhere, drug ,dept stores etc.

I do wear socks all the time. I often take them off after I warm up in bed. I like the feel of the sheets instead of socks.