"I realized that frost doesn't work on machines during my adventures in a dwarven ruin..."
I was making my way through Mzinchaleft with Blisterwort and at the end there was this Dwarven Centurion. Blisterwort specialize herself in frost magic and I thought it would slow it down, making it more easy to kill. Boy, I was wrong.
Blasted machines was immune against frost magic!
Blisterwort made it out alive with just a weak firespell and tons of health potion.(after 13 hours of horror and pain) Still a little shaken though.