Hmmm - I'm torn Rich. Given the destination temp, and the likelihood that it will still be 50s by delivery time, it is pretty tempting to to suggest activating the heat pack and sealing the box when the truck arrives for the pickup. It is a cornsnake, though, and I suspect it would do just fine without one. I'll get off the fence <takes a deep breath, and pushes off> - I would not include a heat or cold pack. Given the starting temps, and normal transit times/procedures, the final temp inside the box would probably be acceptable when it is delivered. (Upon making that decision, I would notify the recipient of it, and my rationale...along with any further instructions - like allowing the snake to come to room temperature vs putting it in warm water, or quickly putting it into a heated cage). Now that it is after the fact - what did you decide??
For the people suggesting that he ask the recipient - not a bad idea, BUT it assumes that the recipient would have a clue...and, IMO, it doesn't remove the responsibility from the shipper. He is the one guaranteeing the live arrival and well being of the animal. As a rule, I am inclined to err on the side of arriving cool, vs overheating in route.
That said - how about this one. I was shipping several pythons today... temps forecast to be around 40 at drop off time, 70 at the first stop, and in the low 90s when it touches down at the destination airport. Drop off to 1st stop is 5 hrs, destination landing is 5hrs later...Heat pack, or no?