This recently published patent describes a box system for keeping medicine, healthcare products and other payloads at a desired temperature for prolonged periods of time. The system generally includes three or more insulating materials between a refrigerant and the payload so that the payload is not cold-shocked by the refrigerant, but instead maintains a desired temperature range during shipment.
An advantage of this method is that the system is effective in controlling temperature without the need for any expensive phase-change materials.
An added benefit of using foldable tabs for securing the materials to each other is also disclosed.
Source: Fresh Patents