I'm new to raising chickens. I live in Massachusetts where it can get cold. I have four 2 year old chickens that got from a friend. I bought a small coop 2 ft x 4.5 ft. it is wired with a 150 watt heat lamp on one end of coop wall. About a foot above roost. i turned it on last night and when i checked the chickens this morning one of them had a couple slightly burnt feathers. Heat lamp had some black marks on it as well. Need advice!! Coop temp stayed at around 43 degrees last night. outside temp was around 32. thanks for any input!!