We don't use fire heat until it gets into the 20's and 30's here.  It's just too warm 
outside for fires when it's in the 40's or higher.   It would make it too warm in the
house.  But on a day like today, we've been burning wood since 7 or 8 AM and
now it's almost too warm in here, even with it being only in the 20's outside.