Haha, I didn't know fire was rated like that. Looks like you taught me something before I could teach you ^^
So as the fire burns it gets hot, that is attributed to the fire consuming the wood. This is the main aspect of fire, it is an element that consumes whatever it can to stay alive. The wind provides a little extra fuel and can push the flame along quicker so it spreads out.
Keep all this in mind as you'll need it in order to replicate fire with your chakra, creating your 'fire' chakra.
Use this new principle as you gather some fire chakra into your stomach, then literally spew out a small ball of fire onto the ground in front of you... I'm going to get some marshmallows ^^
What you want to be careful of here is the timing, you will initially be spewing up fire chakra where it will the become fire at the point it leaves your mouth.