I live about 60 miles north of SF. Tonight is supposed to be the coldest night so far of the winter. It is supposed to maybe get into the teens. Right now it's 34 out side, my coop reads 40 with a 250 watt red lamp on. Tonight is the first night I turned it on. What say you's I've decided to leave the light off tonight. Should I shut the hatch down on the coop. Its 8x8x12 at the peak????