Our brooder is inside right now as it's winter and Michigan has been bitter cold this year. I've build my Coturnix a nice hutch that's in my pole barn right now. I would love to move them into it (and keep the hutch inside until spring) but I don't want them to freeze. When would be a good age to move them into the hutch? Bear in mind, the temp is running around 15 degrees Fahrenheit. Will putting a heat lamp in the hutch be enough to keep them going? Thank you all so much! Just need the latches and steel roof!