Hi,
Couple of thoughts.
Can you describe your quarantine proceedures in regards to these two animals and to your existing collection.
Have you had a PM done on either snake? ( bag it in the fridge before taking to the vets do not freeze it.
What size were both rats and what size were the snakes.
Can you tell us your temps and how and where you are measuring them?
Do these rats smell when they are thawed?
dr del