Heat
The form of energy that has the capacity to create warmth or to increase the temperature of a substance. Any energy that is wasted or used to overcome friction is converted to heat.
Heat is measured in calories or British Thermal Units (BTU's). One BTU is the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit.
In the metric system one calorie is the amount of heat required to raise the temperature of one gram of water from 3.50C to 4.50C (called a small calorie).
If the temperature change is from 14.51'C to 15,50C, the unit is the normal calorie.
