along a fold line 250 to the top panel 134 the set up described above in connection with fig5 creates reactions in the components of the top and bottom front diagonal wall structures and the reactions are represented in fig5 by arrows with dotted tails at opposite ends of the outer side wall 182 there are provided vent slots 252 and 254 one or both of the vent slots 252 and 254 may be provided to allow hot moist air to escape from between the outer front diagonal wall panel 242 and the inner front diagonal wall panel 226 hot moist air is vented from the inside of the container 224 through an opening defined the rear wall 136 and a cut out 256 provided on the inner rear diagonal panel 218 this relationship is better illustrated in fig7 where the flow of hot moist air out of the inside of the container 224 is represented by an arrow 258 the hot moist air is vented to the atmosphere by passing between the panels 210 and 218 and escaping as represented by an arrow 260 through the vent slot 254 this flow of air between the panels 210 and 218 will transfer heat to and raise the temperature of the outside of panel 218 consequently reducing the rate at which heat is transferred through the panel 218 thus the illustrated vent arrangement uses hot moist air to transfer heat to the panel 218 and thereby reduce the rate at which heat is lost from inside the container 224 similarly vents 262 will vent hot moist air from inside the container 224 to flow between the panels.