Thanks for the replies -

We were given an old Zoo Med UTH that lost its adhesive properties and were using it under the tank but it doesn't throw enough heat to do anything...that is why I purchased the Cobra mat. As a temporary fix we had a rubber hot water bottle that we were filling at night and leaving in there. The snake would be wrapped around it sometimes. Just trying to get things right!

If I attached the Cobra mat to the side of the tank rather than using it underneath, would that also work?