Drove for 20 mins in the cold, wore uggs. right heel is semi numb/ feels raw. skin was yellow and cold. other foot is fine. still weird after 2hrs?

Circulatory Problem: If t\you are otherwise a health gal you are describing frost bite. If you are a Type I diabetic it could be pressure necrosis. If, by now you are fine, the prolonged pressure and the cold teamed up to cause your blood vessels to shrink (spasm) for a prolonged period. In surgery we often need prolonged control of blood flow. 4 hours, although maximum, is well tolerated by most healthy people.