Quick question about Sympathy [Spoilers For WMF]

I'm about half way through the book for the first time so be mindful of spoilers please.

During Kvothe's dual with Devi they both seemed to use the energy of fire in order to freeze and control the other person. Am I right in thinking this? I read over it a few times to make sure. Thanks, and sorry if this seems like a daft question.