A packaging system for electronic circuitry is provided. The electronic circuitry may be disposed upon a substrate, which can be encased or otherwise surrounded by one or more components of the packaging system. The packaging system may include (i) an inner housing that can encase or otherwise enclose the substrate within its confines; (ii) an outer housing that in turn encases or encloses the combination of the inner housing and the substrate within its confines; and (iii) one or more gaps positioned between the electronic circuitry, inner housing and outer housing. The gaps may be filled with fluid or solid insulating media. The combination of the inner housing, outer housing, and gaps can insulate the electronic circuitry from the detrimental and destructive heating effects when the packaging system experiences short-term exposure to a high temperature, which thereby allows operability before, during and after such exposure.