Although Cubchoo are far better adapted for the cold than most pokemon, to the point of primarily utilizing ice-type attacks in battle, they are not yet immune to it. Cubchoo grow thick fur to ward off freezing in the cold of winter, but their small size and lack of blubber makes this often insufficient, so many Cubchoo carry an Aspear berry to protect themselves from freezing in dire conditions. The ice which forms within their bodies is removed through the nose as their iconic icicle of snot, which is kept close to the body as a weapon for self-defense.

Should a Cubchoo fall ill, its body will be significantly less effective at removing ice, and its mucus will gain a watery consistency. Cubchoo in this state often collect significantly more Aspear berries than healthy ones, for although a single berry is often used as insurance against a snowstorm, these Cubchoo are perpetually on the verge of freezing, and run through berries like sick humans do tissues.

Trainers often find that, when they remove Cubchoo from their natural habitat, these pokemon appear to become perpetually sick; a few go so far as to return them to the wild, for the sake of their health – while others, puzzled by their pokemon's refusal to take their natural medicine, attempt to force-feed them Aspear berries or Ice Heals. To do so to a domestic Cubchoo is a dangerous mistake, which risks leaving them so warm that they turn into a water pokemon, or worse, melt outright. Although the symptom is similar, watery Cubchoo snot in captivity is typically caused not by an inability to remove ice to the nose, but a lack of ice caused by warm climates, and these Cubchoo are at no risk of freezing.