Ice on chicken's back

[PastaChickenBoo]

Our RIR, Cherry, has a bit of ice on her back. We have our ventilation flaps half open and are scared to open them more as it's very cold outside. What should we do? I suspect this is moisture buildup in the coop.

 

[chickencheeper]

It’s fine, ours have droplets to, it’s just from the bits of snow hitting their backs(after kicking it up) and it melting then freezing on their feathers