Question: If you put a pot of water on the stove to boil,
is this a warming process or a cooling process?
Answer: Neither of the above. Under ordinary conditions,
water boils at constant temperature. It could be described
as an endothermic process. By any reasonable definition,
warming and cooling refer to change in temperature, so
neither is a good description of the process.
Note: This is fifth-grade physics.
Note: Chemists (for good reasons) and biologists (for even
better reasons) tend to assume, unless otherwise stated,
that everything is held at constant temperature, even when
there is not a phase-change involved. Processes roll
downhill in Gibbs free enthalpy space (not in energy
space). This is yet another reason why asking whether
something is a warming process or cooling process is a
Bad Idea.