As temperature increases, the resistance of an insulator typically increases as well. This is due to the increased thermal energy, which causes the atoms in the insulator to vibrate more vigorously. These vibrations can scatter charge carriers (such as electrons) more effectively, leading to reduced mobility and thus higher resistance.
In general, while conductors experience decreased resistance with increased temperature (due to increased thermal energy aiding electron movement), insulators behave differently. The increase in resistance can be attributed to the limited number of charge carriers available in insulators and the increased scattering effects at higher temperatures.
So, for insulators, higher temperatures generally lead to higher resistance, impacting their effectiveness in preventing the flow of electricity.