Mine went outside on their third Saturday...not quite 3 weeks. They had two days of 70 degrees, two nights of 50 degrees and a week of near freezing nights again. No heat lamps, one death the first night. I did bed them with straw the first few cold nights and covered the open portion of the tractor with a tarp.
They can stand quite a bit if they are dry and out of the wind.
They can stand quite a bit if they are dry and out of the wind.