[quote=@Bishop]
It's a "hidden technique" which I learned from the book containing techniques passed down from generation to generation from my clan. This is the only technique written in a book whilst the others are passed down orally but since my character was only a kid he never had the chance to learn even a single one, with what happened and all. But even the book requires a hidden technique of it's own to be read which is only passed orally(else what's the point) and he learned this from his geno-sensei which in turn learned it from my character's father(because sensei is not part of the clan but was considered a brother to my char's father). I would also like to add a sword "secret technique" that he learned from geno-sensei himself while in his run from the Hidden Mist assassins.[@Halvtand]
[/quote]

I like the backstory of this, and the detail about the scroll being locked with some kind of password, it fits with the whole setting very nicely. 
What kind of temperatures are we talking about, really? Is the technique able to create ice and steam or is it bound to "freezing cold" annd "hellishly hot" water? I don't want to be that guy, but since ice and steam are considered KGs in the canon I would need a really good reason to allow a non-KG to have the same effect. 
One restriction I would put on this is that I think your character would've had to share this info with either Hyuuga Hiroshi or another "trusted" and more skilled ninja in Gobi. 
Naruto (ep 1) and the forbidden scroll aside, people generally need guidance and instructions when they learn new techniques to get it right. Because Hiroshi is a jounin (legit) he has the kind of experience needed to actually teach someone from a scroll. 

Secret sword technique, yeah, go ahead, as long as it isn't "totally OP, OMG NERF!" I generally don't see the point in beating something down until I've actually had a chance to see the whole thing. 

[@alexfangtalon] There are a few [url=http://naruto.wikia.com/wiki/Chakra_Absorption_Techniques]chakra absorption techniques[/url] in the canon. Please have a look at those. 
Do keep in mind that while KGs are allowed in the game, they are supposed to be extremely rare, and even more so in a village like Gobi.