The glass appliances are best immersed in warm water for some time before being put to their destined natural use, so I've heard. That is supposed to enhance the sensoric experience. Don't microwave though.
But it might all be different in the US you know. My beliefs received a cold shower when - this was in the early 80ies and in Detroit - a US friend of mine revealed that he insisted that his girl friends were without fillings (in their teeth). The reason given had nothing to do with dental cosmetics, but with the ability to hold a certain amount of ice cubes in one's mouth without thermic discomfort while performing sexual (well, not by any Presidential definition ...) acts on someone else which need not be specified and/or elucidated here. His sister, it has to be said, thought the practice vile and as another piece of evidence in a long line confirming to her that the filling-less girl friend (I have long forgotten her name, but she was a cheer leader, athletic feats ran in the family) was bad company for her brother.
Diese Amerikaner, I tell you ... Against that backgound, other US habits - just think of the prevalent, yet erring practice of circumcision - take on a whole new different meaning. Michigan is really everywhere.