Board Thread:Off Topic/@comment-24534644-20170213012304/@comment-27618538-20170217153457

It is possible but do not expect it to be a swift tactic; you're talking about severe heat exhaustion, and that requires exposure over time without the target taking in any sort of liquids during that time.

Assuming the opponent isn't using dust and if Grimm can be knocked out by such means. I say that because I'm used to thinking of the Semblance as being the soul's best defense/offense against Grimm- granted, I imagine any aquatic Grimm would absolutely hate and loathe heat semblances and anything that hammers them horribly.