Shipping corals and/or fish for 24 hours.

As Rob and Christy said it's no a big deal they've travelled through worse and longer.
We ship all over Canada all the time.
The main thing is keep the temperature stable.
When you buy them, tell them to bag for an extended period.
Your trip isn't even 24 hours.
If the fish are very large, or delicate take extra precautions. If you have a small air pump you can bring with you to areate them during the night that will be helpful.
Also make sure they haven't just eaten a large meal just before you bag them as they may foul their bag quickly.
Good Luck