Abstract: The storage of material that is biologically active such as semen for use in artificial insemination, requires that it be held at a cryogenic temperature at which it is inactive. A package of such a material has a transparent container sealed at one end within which there is a frozen indicator of a color different than that of the material and which has a melting point close to but above a selected cryogenic temperature at which the material is inactive. A barrier is between the material and the indicator and of a type permeable by the indicator if melted and in storage, the indicator containing end of the container is uppermost. The volume of the indicator is such that if the indicator melts, it will flow through the barrier and irreversibly discolor the material as proof that proper storage conditions have not been maintained.