In warm OR cold weather, animals need more than that..
Line the boxes with foam inserts (styrofoam) to help them absorb the shocks and bumps of delivery, otherwise, the delivery itself can kill them from normal handling practices.
The styrofoam will also act to help retain heat or cool, depending on the temps and the time of the year, preventing a sudden heat up or a sudden chill that can shock the animals as well.
Check the temps in your area and the area they are shipping to, to determine if they may need heat packs or cool packs included.
Arriving is one thing, arriving in good condition and healthy is another.
I am sending you a link (in PM) about a similar shipping experience.