I would think if he can walk around, he will not loss his feet. If they were frozen and dead, he would not have feeling, nerve, or muscle control in them, and shouldn’t be able to walk. In my own flock, I have only dealt with frostbie in a few combs and some toe tips, never snything that...
I would bring him to a spot where he won’t be pecked, perhaps to a dog crate with food and water. You can leave it in the coop where he can remain with the flock, or to a cooler spot in your house or garage. The feathered legs and feet are hard to see, but usually the toes are feet will drop off...