Bone-chilling cold that paralysed a-large-part of US this week and caused atleast 18 deaths eased on Friday as-an-errant Arctic air-mass retreated, setting the stage for a warmer-than-normal weekend in areas of Midwest and Northeast. "It's got to be an almost 50 degree difference, it feels like spring," said one commuter heading home from Chicago's downtown financial district, wearing only a sweatshirt to keep warm.