Copper is the best heat conductor of any material used to make cookware.
It heats rapidly and evenly and cools down as soon as it's removed from the heat, giving you maximum control over the application of heat. How quickly a pan responds to a change in cooking temperature is referred to as "responsiveness" and can be a significant factor in choosing what pan will deliver the best results for different jobs.
Since copper is the most highly responsive type of cookware, it is highly prized by professional chefs the world over. The best-quality copper pans are made of a heavy gauge, 1/16 to 1/8 inch thick.