Acclimation

Acclimation is a change occurring in an individual as a result to prolonged exposure of a particular environmental condition, such as a horse shedding its winter coat to produce a lighter summer coat. In general acclimation is a tool in maintaining a being's natural homeostasis.

Tropical fish purchased at a pet store are often kept in acclimation bags in order to allow them to adapt themselves to changes in temperature and water quality.