Wintertime plays a significant role in this novel. When Lia and Cassie were in eighth grade, Lia spent New Year’s with Cassie’s family on a ski trip in Vermont. On New Year’s Eve, Lia and Cassie snuck out into the snow and swore a blood oath to be “skinniest together” (179) compared to the other girls in their school.

The novel begins right after Thanksgiving and ends just after Christmas. As Lia’s eating disorder worsens, this is mirrored by the landscape outside, which continues to grow colder. When Lia isn’t eating enough, one symptom is that she always feels cold. When Cassie expressed interest in seeking help for her eating disorder, Lia says, “when she tried to leave, I pulled her back into the snow because I was afraid to be alone” (99). For Lia, snow and wintertime are synonymous with falling deep into her eating disorder.

Lia and Cassie refer to themselves as wintergirls. When Cassie appears to Lia in the drug store, Cassie explains, “You’re not dead, but you’re not alive, either. You’re a wintergirl, Lia-Lia, caught in between the worlds. You’re a ghost with a beating heart. Soon you’ll cross the border and be with me” (196). Cassie died as a direct result of years of bingeing and purging, and Lia is slowly killing herself by not eating.