Thermal energy is the kinetic energy from atomic and molecular motion in a body. Heat is the quantity of thermal energy transferred to or from a body, while temperature is the measure of how hot or cold a body is. Thermodynamics studies the transformation of various forms of energy including mechanical work, pressure, and temperature. Common devices for measuring temperature include liquid-in-glass thermometers, bimetallic strip thermometers, thermistors, and liquid crystal thermometers.