i hate to say this, but don't jump the gun, irealize you are trying to be realistic, but i would hope to save the one you have, if possssible
not sure if this is what you are referring to, but
we
1st acclimate teh temp by putting the bag in the tank,
2d tehn after @15 to 20 min, we add a little tank water to the bag
3d we repeat
4th repeat
(you get the point)
do ti a couple of times for fish, and several for more delicate creatures, for inverts like stars(or anything delicate) do several doses over a couple of hours, the slower the better, then add the creature to you tank, BUT not the water, you should discard the water(just in case)
HTH