The trees should be packed in some wet material such as sawdust or newspaper strips, and they should be okay so long as they are not left out in the sun. They will steam in the box. I once put a box of trees in the garage and forgot all about them for 10 days. They were perfectly fine and are still growing today.
My cat loves to play under the stool I use when I'm planting. An unexpected grab at my leg is always good for a giggle on her part.