A composition is disclosed which comprises an aryl perfluoropolyether, optionally a halogenated oil, and further optionally a thickening agent. The composition can be used as a lubricant itself or as an additive to an oil or grease lubricant and can withstand temperatures higher than 300° C. without decomposition. The halogenated oil can be a perfluoropolyether, a fluorosilicone, a polytrifluorochloroethylene, or combinations of two or more thereof. The thickening agent can be finely divided silica, boron nitride, clay, soap, poly(tetrafluoroethylene), clay, talc, silica, titanium dioxide, polydimethylsiloxane, polyurea, polyurethane, or combinations of two or more thereof.