I have the same thing from time to time, actually had it tonight to be honest. My feet will feel cold, sometimes numb as well, sometimes just cold. Then all at once they'll go warm. It's hard to explain, but their sensitivity will vary, not quite numb, but not quite 'normal'. Hope that makes sense. At the same time I'll be having other anxiety symptoms, don't think I've ever had issues with my feet by themselves. - Don't take that as an indication as something biologically wrong causing problems with your feet, anxiety has a closet full of disguises and presents itself in varied ways for each of us.