What is a poor conductor of heat?

A poor conductor of heat is any material that can not transfer heat. Poor conductors have a low density thus the particles in a given volume of the material are not enough to collide and transfer heat. Examples of poor heat conductors include air, wood, paper, cloth and water.

All gases and liquids are poor conductors of heat. To demonstrate this principle, place ice in a test tube and fill it with water. Hold the test tube in position, and heat the upper part of the test tube with a gas flame. In this experiment, the water at the upper part of the tube boils for several minutes before transferring heat to melt the ice.