Frozen Fever is a 2015 American animated musical fantasy short film produced by Walt Disney Animation Studios and released by Walt Disney Pictures. A follow-up to the 2013 feature film Frozen, the short follows Elsa as she attempts to throw a surprise party for her sister Anna with the help of Kristoff, Sven, and Olaf. Chris Buck and Jennifer Lee again served as the directors with Kristen Bell, Idina Menzel, Jonathan Groff, and Josh Gad reprising their roles from the first film.
Production on Frozen Fever began in June 2014 and took six months to complete. The film debuted in theaters alongside Walt Disney Pictures' live-action remake of Cinderella on March 13, 2015. It received positive reviews from critics, along with praise for its original song "Making Today a Perfect Day" by Kristen Anderson-Lopez and Robert Lopez.
Plot
One year after the events of Frozen, Queen Elsa is determined to give her younger sister, Anna, a perfect surprise birthday party and enlists the help of Anna's boyfriend Kristoff, his reindeer Sven and the lovable snowman Olaf in order to make sure the party goes ahead without any problems.
Anna is led on a party treasure hunt created by Elsa, following a piece of string that leads to different gifts. The day starts fine but Elsa suddenly starts developing symptoms of a cold. With each sneeze, Elsa unknowingly produces a group of "Snowgies", little snow-babies who begin to dismantle the birthday party's decorations while Kristoff & Sven try to stop them and Olaf embraces them.
Elsa brushes away Anna's growing concern regarding her constant sneezing, assuring her she "doesn't get colds" and enthusiastically continuing the treasure hunt. Meanwhile, Anna is visibly struggling under the weight of all the extravagant presents she has found from the hunt and Elsa's condition is rapidly worsening. Anna recognises her sister is delirious with a fever as they climb the clock tower to Elsa's final present, two figures of the sisters as part of the hourly clocktower procession. Now completely delirious and wobbly, Elsa starts teetering dangerously close to the edge of the platform, before falling. Anna races forward and grabs her sister's wrist, pulling her back to safety. Reluctantly, Elsa admits she is suffering from a cold and that she needs to go home and rest in bed.
They walk back to the castle where Elsa apologizes to Anna for "ruining" another birthday, but Anna reassures her that she didn't ruin anything, despite having a fever. As Anna goes to lead Elsa to bed, the doors to the castle open to reveal Kristoff, Olaf, Sven, and a mountain of Snowgies, who surprise Anna. Elsa sneezes again and finally notices the little snow-people she has been inadvertently creating all day. The cake is served and everyone celebrates Princess Anna’s birthday. Despite her sister's protests, Elsa concludes the party by blowing into an alphorn. However, she sneezes into the horn, forming a giant snowball that inadvertently hits Hans overseas into a cart of manure, as he was cleaning out the stables as punishment for his attempt to kill both Anna and Elsa and take over Arendelle.
Elsa rests in bed under Anna's care while she points out that taking care of her beloved big sister is the best birthday present she could have been given.
Olaf, Kristoff, and Sven escort the Snowgies to Elsa's former ice palace, where they stay with the palace's snow-giant doorkeeper and current owner Marshmallow.