According to the Mayo Clinic, having cold hands even when you're not in a cold environment is common. Often, having cold hands is a part of your body's natural response to regulate your body temperature and shouldn't be cause for concern.
But if you have persistently cold hands, it could be a warning sign. For example, having cold hands could mean you have a problem with the blood circulation in your hands or fingers or a problem with the nerves in your hands. If you are outside in extreme cold weather and you have cold hands, you should watch for warning signs of frostbite.