I think a combination of factors contributes towards being, what my grandmother called, being a 'chilly mortal'
Part of it may be being thin, by that I mean, being underweight, I am not talking about being slim and comfortably within your BMI. That should not lead to you feeling cold.
Other reasons are, I am convinced, genetic. I come from a long run of chilly mortals. I wore cardigans at school when other girls were in their shirt sleeves. My mother and her sister both felt the cold, even though brought up in straitened circumstances, where fuel was used economically. On the other hand I can remember sitting freezing in my sister's house one day, while she was unbothered by the cold temperature.
The other thing that I think contributes to my 'chilly mortal' status is that I have a low normal body temperature. Normal body temperature is generally accepted as 98.6°F (37°C) but "normal" body temperature can have a wide range, from 97°F (36.1°C) to 99°F (37.2°C). Well, my normal temperature is right at the bottom of that scale. 97.0 (36.1) and is sometimes just below it. This can lead to some consterantion when my temperature is taken in medical situations. Again it is genetic, I share that charactaristic with my aunt and probably my mother.
I also have Reynauds Syndrome in my hands, which again means I need to keep well wrapped.
However I do not like over-heated rooms, much prefering wearing extra layers to putting the thermostat up. Our heating is off at the moment and the temperature is just under 18 degrees. I am quite happy with this because I am wearing a lovely warm wool sweater with a shirt over it, a thick wool cardie and thermal socks, and thinking of adding fingerless gloves to the ensemble.