Well it's really well ventilated and dry, we have a poop board with PDZ, pine shavings on floor , the heat lamp is about 6ft off floor sort of over part of roost, they can't jump on it.
I think you could put a heat lamp in your coop without issues. As HollyDuckFarmer and Nigellas said, watch your birds' behavior and adjust accordingly. You really don't want it to be too warm, don't baby them by making it 40+ degrees in the coop. Good luck with your chickens in this misreable cold!
