Flush your cyberpussy with warm water and it should be good enough. If you want something with better usability characteristics, you could incorporate a heating element around the vagninal canal; 3-5W should be enough, depending on the thermal conduction of the material, but it would have be in the form of some sort of expandable weave to cope with the expansion and contraction of the surrounding substrate during thrusting, and reliability would always be an issue due to the relative britility of the heating element. A warm-water chamber surrounding the inner canal might be the best option, and it could be lined with a tougher material than the skin-simulant of the rest of the device to guard against leaks.