Motors become hot because they generate heat through friction and other forms of loss. Many other appliances generate heat this way (and some are designed to ge

Motors become hot because they generate heat through friction and other forms of loss. Many other appliances generate heat this way (and some are designed to generate heat). Conductive materials are likely to be good heat conductors because the electrons themselves can conduct heat, and because the crystal structures of conventional metals (e.g. copper) tend to be good for both. These two effects are entirely unrelated.