I still have a couple of 'stone pigs' up the loftI'm still using a rubber hot water bottle from my childhood, and will continue to until it leaks- the difference being I test the temperature of water I fill it with. If hot enough to scald, I add some cold.... No risk other than soggy bedding.
I also have a collection of historic earthenware and copper hot water bottles which stay hot half the night and will last forever, and although less cuddly are my preference.
My bed has no footboard though, and I'm alway a little wary that I'll push one off the end and crack it on the floor.
They are lovely warm things happed up in a bed on a cold night though