So for those who haven't seen the movie, Anna, the sister of Snow Queen Elsa, accidentally gets cursed by an ice spear to the heart, eventually leading to her death via freezing. Throughout the rest of the movie we see Anna's movements becoming more rigid, her hair becoming white, and frosting all over. It finally ends when she opts to not save her life and sacrifice herself to save Elsa from being killed, turning into an ice sculpture.
Naturally, she is then cured a bit later, as this act was the key of "true love" that would save her. The true love, not of a kiss between a man and woman, but of siblings and family.