Home > Encyclopedia of Science > Temperature

• Words to Know
• Temperature measurement: Thermometers
• Temperature measurement: Scales

The concept of temperature has two related, but different, interpretations. On a general level, temperature is associated with the sense of hot and cold. If you put your finger in a pan of hot water, heat energy flows from the water to your finger; you say that the water is at a higher temperature than that of your finger. If you put your finger in a glass of ice water, heat energy flows as heat away from your finger.

The direction of heat energy flow is the basis of one definition of temperature. Temperature is the property of objects—or more generally of systems—that determines the direction of heat energy flow when the objects are put in direct contact with each other. Energy flows as...