I have always wondered about this, I was forced to have many cold shaved when I went on a 40 day roadtrip and lived in my car/tent and almost always had great results. I too have had a decrease in shave quality/speed over time lately and so I got wondering about the science of it all.
If we have a hot shower, this goes some way to opening the pores and softening the hair, thus allowing a closer shave, however! When heat is applied (to a certain degree) blood vessels become engorged so as to level temperatures within the body, thus swelling the surface of the scalp slightly and preventing the closest possible shave.
I tend to find a bit of both to be true, there is an area at the back of my head that feels smooth until near the end of my shave when my head is beginning to cool and I can finally shave it properly... Thoughts?
