This will be my first winter with batam cochins and was wondering how cold hardy they are.I have three,and they will be in a insulated coop,I do have silkies in another coop that I porvide heat lamps for when its really cold.WIll the cochins need heat lamps?For a few weeks it will be in the single numbers and below 0 at night.It gets down in the teens when the wind is blowing in the big coop, had no frost bite combs on my standard orpingtons,but they are very cold hardy birds.How cold is to cold for the cochins?