You have just come in after a long afternoon of yard work. The summer sun has been beating down on you all day. You go inside and collapse into a nearby chair resting your tired arms on the wooden rests and grasping the metal supports with your hands. Suddenly you notice that your hands feel cooler than your arms, in fact all of the metal in the room feels cooler than the wooden or fabric objects
How can this be?
Actually, the reasons metal objects often feel cooler than wooden objects has to do with the way the body feels heat and the rate metal conducts heat.
If a room is left at 72 degrees Fahrenheit, all of the objects in the room will eventually reach 72 degrees, but a person standing in the same room will be at 98.6 degrees.
When a person touches something in the room, he or she will be at a higher temperature than the object. Heat will flow from the hotter object (the wood or metal). The heat will flow through the wood or metal away from the personís skin, but at different rates, faster through the metal and slower through wood.
We say then that metal conducts heat better than wood does. The end effect is there is less heat left in the finger where it touches metal than where it touches wood. The nerves in the finger sense the finger is cooler and the metal object seems cooler.