I would add newspaper cushioning to the shoe box and put the snake in a pillow case with 1 or 2 crumpled paper towels in the pillow case, into the newspaper cushioned box... Make a secure nest out of the newspaper for the snake in the pillow case.. Then tape a heat pack to the lid of the shoe box and tape the box closed with some packing tape... Before you do all this you should add ventilation holes to the sides of the shoe box with a screw driver..
Basically package up the snake like it was being shipped, out of some easy materials for a short trip... (Obviously never ship an animal in a shoebox, but this will work for a short trip)... Also, pack an extra heat pack to tape to the lid of the box for your return home!
~Brandon