Our coop is raised up off the ground, about two feet, and there are holes we drilled that we are planing to seal to keep heat in firming the winter. We live in central pa, south of Harrisburg, and it gets pretty cold in the winter, into the negatives. I was wondering if I need to add supplemental heat to the coop, and is so when. We are getting a heated water that will stay outside with the food ( in the run). We covered 2 sides of the run with clear plastic to keep some heat in and the frigid wind out. Any recommendations on how to keep the chicken warm??