Quoting Bernard Cleyet <bernardcleyet@redshift.com>:
I thought we decided not to use that word except as a verb.
Thanks for all the responses. The usage of the word "heat" may not be
agreed by all physicists. For example, John Denker may not agree.
Interestingly, In one engineering text, the operational definition of
heat is defined via Born-Caratheodory form of the First Law of
Thermodynamics. Then one paper in the context of Chemistry, proposed
qualitative and quantitative definitions on heat. The quantitative
definition on heat can be defined, for example, with the use of
Calorimetry.
In a recent PhD Thesis on the role of language in learning physics,
the operational definition of heat is considered to be the energy
transferred between objects because of a temperature difference, and
heat is preferred to be a process. This seems inconsistent to me. If
heat is a process instead of a noun, how can it be measured? Besides,
this common textbook definition does not involve any explicit
operational procedure. How could it be categorised as operational
definition? At least, the chemists mention calorimentry.