Circulatory conditions, such as cold hands and feet, parasthesia (sp?), or pins-and-needles, light-headedness - it's all symptoms your body is struggling. When you purge you overheat the body's core which temporarily increases your pulse and draws blood into your oesophagal lining in order to try to heal the throat. Do this often enough and your body starts to take a lower blood pressure overall in an attempt to regulate.
What results is a feeling of freezing-to-hot polarising feelings, dizziness as your electrolyte imbalances heighten, you starve your inner ear (balance centre) of blood and occasionally find you "lean as you walk", and eventually it worsens. And trust me, it worsens.
Even if you DON'T purge, because I only ever did so a few times (but it was never really about that for me), these symptoms just occur as your body starves in general.