A container for containing a freezing bag filled with biological tissue and for cooling and warming the freezing bag. The container includes a main body possessing an inner surface, a first side surface and a second side surface positioned opposite the first side surface. The main body is substantially rectangular parallelepiped shaped. The container includes at least one opening in at least one of the first side surface and the second side surface of the container, and at least two ridges spaced apart from one another on the inner surface of the container to create an air gap between the spaced apart ridges, the inner surface of the container and the outer surface of the freezing bag.