As far as I know, the human body temperature is meant to be around 36-37C. Is that an external or internal measurement? If it’s not the external temp, is that because external temperatures vary between individuals? and would this be why I seem so much colder than, like, everyone else I know?
I’ve noticed for a long time that whenever I sit in a recently occupied chair or touch something where someone else has been in contact for long enough to warm it, that it feels really warm to me. Much warmer than if I touch a seat I’ve just been sitting on - which will usually feel slightly above room temperature.
I know I have poor circulation, and in even mildly (by Northern standards) cold weather, I start developing chilblains on toes and fingers (my hands are almost always cold, and I do have some kind of RSI issues too, which I suspect either worsen, or are worsened by, the cold problem :(). Is there anything I can do to increase my body temperature? Is it a medical condition, a nutritional problem, or just the way I am?
Visit a sauna 
Most people find that chairs are warmer when someone else has sat on them than when you did. This isn’t a temperature issue, its an expectation issue- you expect the chair you just got up from to feel warm; you don’t expect the chair you haven’t sat in yet to.
Those are questions you should be asking your doctor.
QtM, MD
37C (=98.6F) is an internal temperature. Average skin temperature is about 30C (=85F).
My mom is a human icebox. Always had very cold hands and toes. Shes also healthy as can be and she works out three times a week. Its just the way she is. No med problems. Ever.
My father-in-law has a similar problem. He takes meds to improve the circulation in his extremities. Not sure what it is though.
My wife has it to some extent. We have to keep the house warmer than I feel is comfortable or she gets cold hands, feet and nose.