Why do metal cooking utensils often have plastic coating on their handles?
Get a long metal spoon, and use it to stir the soup..............
What happens? Soon, the spoon gets too hot to hold.
Replace the metal spoon with a wooden spoon. You can leave the wooden spoon in the boiling soup; it does not get too hot to hold. Why?
Clearly, a metal conducts heat much better than an insulator. A plastic handle, a good insulator, on such utensils reduces the conduction of heat to your handsies. A wooden spoon is another poor conductor or good insulator, and it serves the same purpose.