The property of metals that necessitates wood or plastic handles on metal cooking utensils is thermal conductivity. Metals are good heat conductors. They have low heat capacities compared to other materials, which means that they experience a greater temperature change than other materials when absorbing the same amount of heat. Metals have electrons that move about more freely in than in other substances. When a section of a metal object begins to heat up the moving electrons help transfer the heat more efficiently. This process of heat transfer is called conduction.
You may have noticed that metals feel cold to the touch in cold environments. Heat is being conducted from your skin to the metal when you touch it. If you hold something metal in your hand, such as coins, they warm up quickly as they absorb heat.