The correct way is ARE your feet cold. Since you are refering to the plural noun, feet :)
I am not exactly sure, but i think it is because you lose most of your body heat from your feet, which makes them colder.
John was very eager to do a bungee jump, but when he seen the height he'd have to jump he got "Cold Feet"
you say get cold feet . some people might say it's have cold feet , but for me , get cold feet makes more sense .
Put on socks. Or, like I did this morning while getting ready for school, stand on the heater. (we have electric heat, which comes up in vents). I also have tried using a blow dryer when I was drying...