I have a broody hen on twelve eggs that she is due to hatch the first part of April. The daily high temperatures are expected to be in the 50's but the nights are cold with lows in the 20's. Would it be advisable to hang a heat lamp in the coop if I keep the hen with the chicks? Or do I let mama handle everything with regard to cold exposure? Thanks for your advice; this is my first time with a broody.