The term 'heat measure' can refer to two different units of measurement: the CALORIE and the British Thermal Unit (BTU). A CALORIE is a unit of energy that is used to measure the amount of heat required to raise the temperature of one gram of water by one degree Celsius. The BTU, on the other hand, is a unit of energy used to measure the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. Both units are commonly used to measure the energy content of food and other substances.