Abstract: The present invention relates to a device for use in maintaining a temperature in a vehicle or a shipping container. The device includes a roller having a sheet attached to the roller. One end of the sheet is connected to the roller and the sheet can be rolled around the roller and unrolled from the roller. The sheet has a size such that the sheet can extend substantially transversely across the cargo area of the vehicle or shipping container when the device is mounted on the vehicle or shipping container and the sheet is unrolled from the roller. The device allows for a user to simply unroll the unattached end of the sheet from the roller when the user needs to load or unload goods in the cargo area of the vehicle or shipping container in which the device is mounted.