Buyers and sellers of glassware (especially fragile vintage glass) on eBay should be aware of a phenomenon called THERMAL SHOCK.  If a piece of glassware experiences sharp changes in temperature, it can shatter no matter how securely packaged it is.

There have been several reports of thermal shock destroying pieces mailed to cold weather climates.  Typically, this happens when a package has been left out in the cold (for instance, on the customer's doorstep or on a long truck ride) and then the package is suddenly opened in a warm room.  Witnesses report hearing a kind of sucking sound followed by a cracking noise.

To prevent this from happening, BRING YOUR PACKAGE TO ROOM TEMPERATURE BEFORE OPENING.  If you are mailing a fragile item to a cold weather climate, it's prudent to email the buyer and let them know about this.  It might also be useful to put a warning next to the address label.  Better safe than sorry.  Good luck!