Is the temperature of an isolated system (no interaction with the environment) conserved? Explain.

Yes, the temperature of an isolated system is conserved.
Temperature is the intensive property, because it does not change with a change in the amount of substance in the system. A system in which neither mass nor energy can cross the boundary is called an isolated system. So, there is no transfer of heat and mass in an isolated system. Therefore, no transfer of heat in an isolated system signifies that, the temperature of the system is conserved.