Heat cable in cast concrete.

First off, english is not my first language, so please bear with me:)

Now, have anybody cast in a heater cable in concrete? The thought beeing that concret carrys heat better than air, therefore raising ambient air temp better on both hot and cool side.

Im considering doing this with a exo terra 36x18x18, and just put the concrete block inside the terrarium buried in substrate. Im also thinking it may reduse the risk af glass cracking due to heat.

Thoughts on this?

Have a nice weekend!

/Aldhissla