I've noticed another possibility with regards to impeded circulation - one that works with my own physiology.
I've noticed, especially with the seasons, that when the body is cold when environmental conditions suggest that your body should be ok, that the sodium to potassium level is off. If I'm overly cold, I eat something that will supply sodium/yang (something salty), if overly hot, potassium/yin (powdered maca works for me). Perhaps another approach!