You should see a doctor and have a good history,physical exam and laboratory tests in order to find out why you feel cold and receive appropriate treatment

Low thyroid can make you feel that way.

There could be many causes. Too many to explain all here. It could be thyroid, heart, blood vessel disease & many others. It could also be lack of insulation i.e. fat. My wife is skinny & always cold. I am a little overwt. thus have some fat to insulate me & keep the eat in, so I am always hot. We fight the battle of the thermostat every day! Please see your DR. and get checked. It may be nothing or it could be serious so get a check up soon.