It's been a couple years since I went through the process so I don't know if anything has changed, but I can answer based on my experience. They DO check that the bag is secure, so set the bag up however you would if there was a snake in it. The heat pack wasn't needed, but I did tape one in there anyway, unopened. Temperatures that you would ship at wasn't needed. Basically they just wanted to make sure that the box and bag was secure for the minimal chance of a snake getting loose. When I did my test the form I had to fill out had a box you could check if you wanted the box returned to you.