[quote=Schradinger]
135 degrees Fahrenheit isn't that hot. It almost gets that hot around here in the summer, and fire at that temperature wouldn't even be uncomfortable for Arty. I'm not even sure if it would cause most woods to ignite, and it definitely wouldn't do anything to the magical oak tree. I'd recommend looking up napalm and adjusting the temperature to somewhere in that range, though maybe adding in that he has to build up (or charge) the attack for X number of posts in order to reach max temperature.
[/quote]

Perhaps 135 is the base heat?

And the more the magic is charged, it gets hotter and hotter.