Water is a poor conductor of heat, and is actually classified as an insulator of heat. Materials that are good conductors of heat and of electricity must have free electrons that can carry the energy from one compound to the next.
Water, plastics and any types of glass are not good conductors, and are actually insulators because they do not allow electric or thermal charge to pass through their materials. Conductors must allow electrons to freely move from one compound to another, while insulators stop the flow of electrons. Good conductors include most metals because of the number of excess electrons they contain.