How is Fred represented in A Christmas Carol?

Scrooge is represented as being incredibly cold, both emotionally and physically. The narrator says that he is

Hard and sharp as flint, from which no steel had ever struck out generous fire . . . . The cold within him froze his old features, nipped his pointed nose, shrivelled his cheek, stiffened his gait . . . .

Scrooge is likewise unfeeling and utterly lacking in compassion: someone we'd certainly describe as "cold." However, Fred, Scrooge's nephew, is represented as being warm, both emotionally and physically. When he walks into Scrooge's counting house, the narrator says,

He had so heated himself with rapid walking in the fog and frost, this nephew of Scrooge's, that he was all in a glow; his face was ruddy and handsome; his eyes sparkled, and his breath smoked again.

Where Scrooge is cold-hearted and callous, Fred is warm and kind. He "glow[s]" from his walking, an activity which has "heated" him bodily, and his handsome "ruddy" face betrays his generous and loving nature. He invites Scrooge to Christmas dinner despite Scrooge's unpleasant rudeness. Fred is the example of what all Christians should be like at Christmas and the whole year long: kind, loving, and happy to help others.

In Charles Dickens's novella A Christmas Carol, the protagonist, Ebenezer Scrooge, is represented as a cold and uncaring character. He is only concerned with himself and with making and saving as much money as possible. He is not even concerned about spending time with his remaining family members, such as his nephew Fred. By contrast, Fred, his nephew (and son of his late sister), is represented as a caring and empathetic character who is almost entirely opposite of his uncle Ebenezer. While Ebenezer Scrooge shows little interest in helping others and spending time with his family (at least until the end of the story, when he has changed dramatically for the better), Fred invites his uncle to his house for Christmas dinner, knowing that Ebenezer will probably not show up; every year Fred invites Ebenezer to Christmas dinner, and every year Ebenezer declines the invitation. Even through Fred has not been treated well by his uncle, he remains caring, inclusive, and empathetic. Fred, therefore, serves as a dramatic foil, or opposite, to his uncle; they are so different that the way in which each is represented highlights the other's opposite characteristics. (By the end of the story, after Ebenezer has changed because of visits by ghosts of Christmas past, present, and future, Fred and Ebenezer share the traits of empathy and compassion for others.)