I'm torn about this, not sure what to do. Climate is Iowa. I am using general purpose sand for the coop floor. With some very cold temps right around the corner, should a guy switch over to pine shavings or the like to keep the floor warmer? My coop is 6X8 for 8 large breeds built on a 5 inch concrete slab. Pretty sure that floor will get might chilly with the concrete/sand. Appreciate any responses.