Yes I am curious also! What does a frostbite look like? I imagine a white comb..
Also, I've seen many thread about frostbites, but how to you treat them? Anything special we need to do if it ever happens? I guess not, it is not like an exposed wound.
My last dumb question... you all have nice rooster that let you pick them up and put vaseline on their combs?!?! Not sure mine would appreciate. I think I would probably chase him around everytime I need to put vaseline on. At the end of winter he'd probably hate me from chasing him all the time!
I personally feel there is no such thing as a dumb question. Dumb answers maybe... Hopefully my answer ain't one of the dumb ones.
You can try going into the coop after dark when they are all roosting. Use a small and/or dim flashlight so you don't have to fumble around in the dark. I use an LED headlamp I bought from the Dollar Store for $2.25. I just use some electrical tape across the lens to decrease the lumens(brightness of the light).
Use the voice you always talk to your chickens in(unless you're always yelling and cussing at them[I've known people that do]). Use your "talking kindly voice" but lower the volume. Move slowly,gently. Fast movements startle birds. Slowly get ahold of him. If he starts to squawk put you hand over his head and rock gently. He should settle down. If not, just take him outside and still keep talking to him gently and start applying the "frostbite minimizing gel". He will eventually calm down. When you're finished take him back to his place on the roost and gently put him back there. Make sure his feet are on the perch properly.
Remember.... slow movements, unless of course you fumble and he starts to run/flap himself to freedom away from you, in knee deep snow, in subzero weather, causing him to get lost overnight, freezing to death, or getting caught by a fox, or if he's unlucky enough to survive till morning that finds him not only with a frostbitten comb and wattles but also with frozen feet and/or legs only to finished off by ravens.
That may sound like a horrible joke and/or an awful "hypothetical" scenario but in reality this can happen when we choose to raise barnyard fowl in weather that they were definitely not evolved for. I'm merely speaking from experience.
I, also personally, think that the only way we are going to alleviate the problem of freezing combs and wattles and feet is to create some kind of "truly North American" cold hardy dual purpose barnyard fowl is by using Ptarmigan/Leghorns crossed to Ruffed Grouse/BuffBrahma or something along those lines.
Just watch, someone will try now. You'll hear about it in some years to come. "Amazing breakthrough......"

Another hypothetical scenario....albeit not as likely to happen as Frank Sinatra(my rooster who had a beautiful soft crooning crow)flapping away
to "the ultimate" freedom.
A frost bitten comb is white"ISH" while still frozen. It turns to a pink water blister looking thing
then black as it dies. Same thing with wattles and toes.
If it wasn't too bad I would bring my birds in the house and put them in cold water.
If you "thaw them out" with warmth(hair dryer or warm water) it seems to intensify any damage.
But we've found that if they get frostbite once, it comes easier next time. Now, instead of having a bunch of " house chickens" we just dispatch them for soup or roast as opposed to letting them live a long life of being crippled and/or horrid pain and being persecuted by the rest of the flock...... .....Again, from experience.
Please be cognizant, even though my grandparents tried telling me all this, when I got birds I did my darnedest to prove them wrong. Life taught me them old people of course were telling me the truth.
I know.....long story. I hope it helps though