Looking at the wiki, there appears to be a freeze damage for trigger_hurt, but it does not appear in game. Entering it's value (16) just changes the damage type to generic. Slowfreeze is pointless, as it just leaves an extra body floating in the air.
So is there no way to do freezing damage? I just want some freezing cold water
So is there no way to do freezing damage? I just want some freezing cold water