Heat resistant systems provide a self-activating insulative solution. A seal system includes a case defining a joining line where two sections of the case join together. The case envelops an internal space and separates the internal space from an external space. A seal is disposed at the joining line and a case extension defines a cavity on an outside of the seal. The case extension has an opening that extends between the cavity and the external space. A lining of a heat responsive material is provided in the case extension. The material expands to an activated state when exposed to heat above a threshold temperature and passes through the opening encapsulating the case extension and insulating the seal from the external space.