A thermal barrier for helping to maintain a temperature in volumes and/or at least one internal structural component surrounded by the barrier. The barrier has a first component containing at least one phase change material (PCM) that changes its state at a first temperature, a second component containing a PCM that changes its state at a second temperature which is different from the first temperature, and a third, thermally insulating component that is disposed between the first and second components containing a PCM or outside the second component.