While I agree that Height is not a simple value type (it is not self-identifying), I'm afraid I don't see that it is actually an entity type:
- You can't point to a Height and say, "look, there's Height 60 inches" in the same way you could point to "Person named John Saunders"
- What happens when the Height changes? My brother is an inch taller than I am. If he loses an inch with age, do we suddently both share the same Height instance? What happens to the original instance? Is it now orphaned?
For 1 you can actually point and say that there is an instance of Height and for 2 it is not the height that changes, it is the height measurement that changes.
According to the
philosophy adopted by the
BFO ontology (described in earlier post)  there is one upper level
category named "Quality" that represents the things that we
commonly refer to as "properties". The "BFO:Quality" is a
subcategory of higher level categories named
"SpecificallyDependentContinuant" and "DependentContinuant",
which represent the categories of things that depend in their
existence on what is called "IndependentContinuant".
The BFO framework says that each one of us has a specific instance of the Height entity (that
could be assigned some unique identifier if needed) that never
changes. I have one instance of Height when I started to exist and the
existence of my Height instance depends on my body's existence. My
body is an instance of an IndependentContinuant that "bears" and
instance of Height.
My instance of the
Height entity is not the same as the various instances of the
HeightMeasurement entity that are obtained/created about my Height
instance at various times. There is a common confusion in the medical field about entities
that are not about something else and entities that are always about
(not property or quality of) something else. My single instance of
Height is not about anything, it just exist , regardless of whether
there are any instances of HeightMeasurement about my height.The same thing applies to blood pressure vs. its measurement, pain vs. the subjective assessment of it, etc.
This approach is
being formalized as an extension of the BFO in the form of the
"Information Artifact Ontology (IAO)"  to develop a general
formal representation of "informational entities" that are always
about some other entity. It is within the IAO that values (labels of
values to be more correct) become useful.
Taking Height as a
simple example. Height is a one dimensional quality (a Length with a
topological orientation) that could be assessed or measured by
marking a point on some other one dimensional entity. We do this when
we ask our kids to stand against the wall and mark a point on the
wall to watch them grow. To make this idea of assessing a Height
instance more formal, we would use the straight line axioms from
geometry and try to mark points on a line to "measure" a Height.
However, we still need a way to describe where this point is on a
line and this is where it becomes useful to divide the line into
standard discrete parts (the various length units) and then use the
system of numbers to identify how many parts are being used as a
measurement for an instance of Height. We could also decide to only measure
in discrete units and then predefine a standard set of named points
on a line and give them randomly created strings as labels. However,
by using integers, and the properties of their axioms, we would greatly
simplify measuring length and enable us to add and subtract
measurements in very useful ways. This same idea applies to
Temperature vs. TemperatureMeasurement and most of the other entities
that need numeric or string "values" to make an assessment of, or
a reference to, some other entity.
I went into too
much detail about measuring a height as an example for how to be
formal in measuring qualities and to show how value systems (or value
sets) and their axioms become useful when we create informational
entities about other entities. The height measurement case is very
straightforward but many qualities and qualitative assessments in the
biomedical field are very difficult to analyze and represent in a
formal way. I am still learning about this issue but  would be an
interesting reading and a good start for anyone trying to develop a
clear formal approach to this problem.