Abstract: An insulated container for shipping perishable products is provided. An insulated container system (10) includes a telescoping container having a top (14) and a bottom (16). The top (14) and bottom (16) are each formed from a rectangular sheet (28) of corrugated cardboard. The sheet (28) is coated with wax to repel moisture. The sheet (28) is folded inwardly to form corners (41A-41D). Inwardly folded sections (44, 46, 48, and 50) form multilayered, triangular regions of side walls (38A and 38B). Single layered central side wall portions (52A and 52B) between the multilayered regions are trapezoidal. A one-piece insulating liner (18) is formed by folding a sheet (58) of expanded polystyrene along creases. The one-piece insulating liner (18) has trapezoidal side walls (62A and 62B) and rectangular end walls (60A and 60B) that form an integral structure with a floor (64). The one-piece insulating liner (18) is inserted into the bottom (16) and covers single layered portions of the bottom (16).