The 40 watt bulb shined across the opening of the huddle box will keep them warm. Again, close the garage off before the temp drops to keep the heat in. They should already have their wing feathers and should be feathering in well. Overheating them slows this down. You just don't want them to get cold.Tomorrow night the lowest temp is 65 can they still use the huddle box or should i use the 40 watt bulb in the heat lamp