Like it says, why do people ship their snakes with cool packs?

It just seems like if your shipping over night in the dead of summer, the temps are much cooler and comfortable (sometimes too cool), and having a cool pack in there isn't going to do much good if the package is dropped off in the morning.
And maybe it makes it much too cool for the snake during the overnight leg?

BUT, if the package doesn't get dropped off by 10:30 in the morning, and it does start to get pretty hot, wouldn't the ice pack be completely melted by the time it's really hot (say noonish) and be worthless?