A key some people overlook, your extremeties start to get cold when your core starts to get cold. The body then keeps the blood closer to your core because thats where your vital organs are. Keep that core toasty warm and it willHELP your hands and feet.
I'll second that, I know lots of people who wear the warmest boots on the market yet their feet are still cold because they don't keep the rest of them as warm as they should.