A thermally resistant article includes a structural body that is formed of a heat-sensitive core and a thermal protection layer on the exterior of the heat-sensitive core to provide thermal shielding. The thermal protection layer has a thickness and a composition such that the structural body meets a target strength-thermal performance criteria upon transient exposure to a heat source. Without the thermal protection layer, the heat-sensitive core does not meet the target strength-thermal performance criteria. The composition includes a polymeric material mixed with microspheres.