An Ice Guy

is a Side Quest in.

Overview
In the Kara Kara Bazaar, Link will encounter a Rito named Guy who has no will to continue traveling due to the Heat of the Gerudo Desert. He mentions to Link that he has heard of an Elixir that could help him made from insects with cooling effects and monster parts. After Link is done talking to him, he will receive the Side Quest. In order to complete the Side Quest, Link must cook chilling insect and monster parts together and come back with the resulting Chilly Elixir. Guy will thank Link and reward him with a Purple Rupee.