You stole my line Bisithorious.

You see he has very sleek and smooth hair. Its practicaly dripping with moisture, therefore even in the most intense heats it stays nice and cool (somebody like cloud for instance would burn like straw with his dry hair) and his clothes just came out of the washing machine (hey, if your going on a killing spree you dont want to have last nights nasty ketchup stain on show.) Now his skin would be tough and covered in calisis due to the constant fighting and would be virtualy nerveless. The woods itself would be from realativly young tree's (as the materia keeper is terrorising the upper reigons of the mountains, not to mention the random encounters loggers would encounter causing the area for chopping wood to be restricted meaning that the trees they cut down would have to regrow for the next generation of houses) as such the wood would burn much more slowly meaing that the fire is cooler than an average fire.

There. Is that a good enough explaination for you?