I am setting up my first grow out pen, it is a horse stall that I have covered in hex mesh to keep anyone from flying out. It is located within a secure horse barn, so I am not too horribly concerned with predators at this time. My question is, the chicks who will be moving into this 12x9 grow out pen, are about 5-6 weeks of age. They are almost fully feathered except the cockerels (who look naked...). I have purchased a chicken mat heater to provide heat to any chick that gets chilly. The problem is, we are located in Wisconsin and for the next two weeks the nights are supposed to be in the mid to low thirties. Is the chicken mar heater going to be warm enough for the not so feathered cockerels? I really need to shift them out of the brooder that they have outgrown... Plus I have more chicks moving into the outside brooder out of the baby brooder which will hopefully be filled again after this hatch. I refuse to use a heat light in my barn (I will not risk all my horses and chickens...). Thanks in advance!