Abstract: A passive refrigeration box for controlled refrigeration of a product comprising: an outer box including an outer insulation layer; an inner box including an inner insulation layer, and a thermal shield on an outside of the inner insulation layer, the inner box and the outer box defining a vapour channel therebetween; and a thermal link including a thermal layer and a plurality of heat pipes or thermosyphons, the thermal layer and a top section of the inner box defining a coolant chamber, the coolant chamber including a coolant chamber access, and in communication with the vapour channel, and the thermal layer and a bottom section of the inner box defining a load chamber, the load chamber including a load chamber access, each heat pipe or thermosyphon having a condenser section disposed in the coolant chamber and an evaporator section disposed in the load chamber and extending through the thermal layer.