On the first page of this section, you started an activity:
Check that one of your pieces of thermal sensing sheet has a color somewhere between tan and blue-green at room temperature. If not, find a room for which this is true, or bump the thermostat. Choose some items that you expect to feel cool -- the file cabinet, a metal ruler, a glass jar, ... -- and some that you would not expect to feel cool -- a newspaper, a towel, ... . Leave the items undisturbed in the room for a few hours.

Now check that the thermal sensing sheet is the same color that it was, and use it to see what temperatures the objects are. You have calibrated the thermal sensing sheet, so any significant differences from room temperature should be easy to detect and determine. After you have determined the temperature of each object, feel it to see how cool it feels. Try to make a generalization, which items feel cool and which do not.

Summarize your observations: Were the initial temperatures (before you disturbed them by touching them) the same or different? Is there a pattern in the differences? What does feeling warm or cool have to do with the temperature of the object? How do different objects respond when you touch them?

Next: Find the conductor