High temperature dielectric capacitors are industrial grade

KEMET Industrial Grade High Temperature X7R Dielectric capacitors can utilize the full rated voltage at 175 Celsius. Devices provide highly reliable base metal electrode system and come with a flexible termination system option and are RoHS compliant without exemption. Products are well-suited for a variety of applications in extreme environments and provide higher capacitance values in smaller case sizes compared to competitive high temperature products, thus saving valuable space on circuit boards.

http://www.kemet.com/X7R-175