So, what are the problems with liquids freezing on aircraft? The answer "use more water" is neither correct nor sensible.
If I saw someone "defrosting" their aircraft using plain water of any temperature, then I'd hit them with sticks until they went and did some research into why it's such a bloody stupid idea.
Seriously, I cannot believe that people can even consider using water to defrost a cold airframe and then go flying into even colder temperatures...