A device including a heat-absorbing component, and one or more heat-generating components. At least one heat-generating component is located in proximity to an inner surface of the heat-absorbing component, and a gap exists between the at least one heat-generating component and the inner surface of the heat-absorbing component. The device further including an insulator, located in the gap, including an insulator structure enclosing atmospheric pressure gas, where the atmospheric pressure gas has a thermal conductivity lower than air.