In a dynamical treatment of heat balance between metabolism and environment, a method must first be found of completely separating the 5 elements of partition so that each has an individual significance in relation to certain easily derived physical and physiological measurements; the many interrelationships between these elements must then be examined for various physical conditions. By means of the First Law of Thermodynamics and certain physiological and physical assumptions the interrelationships between the elements of partition and their basic variables are formulated. This partition is next analyzed in such a way that a linear relationship between certain groups of basic measurements holds only when all the assumptions are valid. When this linearity criterion is satisfied, each element of partition may be studied in terms of its fundamental measure. Furthermore, the interrelationship between all the elements themselves is completely presented both qualitatively and quantitatively. Where this criterion fails, there is a probability that an error exists in one of the basic partitional measurements. It has been shown[long dash]in one special case[long dash]that for such deviations toward the colder conditions there is an error in the storage measurement, while for the hotter conditions, there is an error in the evaporative measurement.