Water temperature varies under pressure

Question

We have a shower with a shower head and a hose turned off by a valve at the top of the pipe leading to the showerhead. Over the years I've noticed that if I leave the hose turned off while showering, then turn it on, that the water from the hose is significantly hotter than what's coming from the showerhead. The temperature moderates after a second or two, long enough to clear warm water from the hose. The same thing happens if I leave the showerhead turned off, then turn it on after a while.

I was willing to live with this question unanswered for the rest of my life, but my son just asked me what was going on. So can anyone help me look like a star to my little boy?

Jim

Answer 1

Your title seems off. Pressure will not affect the temperature of a solid or liquid. ( May change boiling/freezing temp of liquid. )

A possible cause may be  that the water which is stored up in the pipe does not leave, so it stays hotter. ( Not too sure )