Is your bathroom chilly in winter? The the patented invention of Mr M M Gravin would be just the thing for you, despite the fact that the purpose of the invention was to provide for a more even shave.

It is a well-known fact in having with a razor that the heating of a razor blade, makes the razor blade out just that much better in shaving the beard. For this reason it is a frequent practice to dip the razor whether open edge or safety razor into hot water before the user shaves. The lather on the face cools the razor and lessen; the efficiency with which it cuts. This makes it necessary to frequently dip the razor in hot Water as the shaving progresses and makes the shaving uneven.

It’s not a well known fact any longer, so I’m not sure if this claim was pure hogwash or if it actually did make a difference with carbon steel blades.