total heat vs heat content

total heat and heat content both are nouns.

Word	Noun	Adjective	Verb	Adverb
total heat	Yes	No	No	No
heat content	Yes	No	No	No

As nouns, total heat and heat content are synonyms defined as:

total heat and heat content: (thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure

Other synonyms of total heat include enthalpy, H.

total heat (noun)	heat content (noun)
(thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure	(thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure