Use snakebags if you have 'em...if not, pillowcases turned inside out work fine, too. Be sure to use one bag per snake...but I think it's ok to put the bags in the same box, so long as none of the animals are in quarantine. (If so, the quarantine animal needs its own box.)


Make sure the box is insulated with styrofoam (as already suggested) and add some other material to fill it out and cushion the snakes to keep them from shifting around in there as the car moves.

If you wanna get fancy, get an acu-rite digital thermometer...place the probe in the box and the unit on top of the box...then you can check on the temps inside without having to open the top. So long as the temps stay around 80 degrees in the box, the snakes will be fine for the duration of your trip. Even if you stop overnight...just carry the box into the room with you, then back out to the car. No need to take the snakes out of the bags.

The most important piece of advice:
Never, ever, even for 3 minutes, leave the snakes alone in the car during daylight hours. It will heat up faster than my home oven and can become lethal literally within minutes.

I traveled cross-country with my animals by myself once and I carried an extra set of car keys so that when I made a bathroom stop (which I made an effort to keep to a minimum) I could leave the car running but still lock it up....dash in and use the restroom, and right back out again. Meals were taken by way of drive thru. Once the sun went down though, it got easier.

Or...you can find someone to ship 'em for ya, as Robin suggests.

Good luck!