Good gracious Gurney, we all had those beige-coloured stone china hot water-bottles just after the War. Nobody had a rubber one.

You're right about getting burned when you touched it. My mother used to wrap ours in bits of old army blanket. Kept the heat in a bit too.

With absolutely no heating in the house (except for a small coal fire in the sitting room) a hot water bottle was essential. There was always ice on the inside of our bedroom windows in the morning. Lovely fern-like frosty patterns.
We also had a china 'jerry' for use as a toilet during the night. It went under the bed.
I can take any heat or humidity whatsoever. Love it. But I am careful about not getting burned in the tropical sun. Don't want melanomas!