Also instead of using the heat packs you can use water or pop bottles filled with hot water, or cooler water depending on the time of year it is.
I just recieved 3 ball pythons, and the way it was packed was a cardboard box lined with styrofoam, hot water bottles on the bottom, shredded newspaper, and the snakes in a small rubbermaid container also filled with shredded newspaper.
It was only suppose to be a 5 hour trip but Air Canada screwed up and it turned into a 10-11 hour trip and the snakes where still nice and warm. and by the way it was also -20.
[10:12pm]«@ [Matt]» he's all up in there like swimwear.