I feel for you. We also had a coop fire with smoldering and it was the smoke that killed and damaged. No vets who would deal with chickens. This is what I put together - being an RN helps, I just did what I would do for a human. First, keep the airway open. I had to use my daughters asthma inhalor (bronchodilator) for the wheezy ones. I did 2 puffs one minute apart by dispensing the puff in front of the face while they were breathing in. Be careful you don't get it in their eyes, go from the side, not too close to the face. For a chick, I'd try one puff only. Also, start a respiratory antibiotic because infections are opportunistic. Push fluids with electrolytes added. Don't overdo the dosage of the electrolytes because that's not good either. Follow the package directions. You might have to use a dropper or straw to put some in if they're not drinking. Look inside the mouth and throat for burns. Be aware smoke can also damage eyes and affect vision. If the chick gets progressively worse with wheezing, and the lungs start filling up, you may have to do the humane thing, as hard as it might be. With treatment, I had complete recovery of most, but I did have one almost blind rooster, and a few hens that were never the same, and they ended up dying of something else not long after. I learned the hard way about heatlamps. If there is a way they can knock it down they will, and often the cheap ones just aren't safe to begin with. Oh, For 2 of my chickens with continuing wheezing, I also used a steroidal inhalor for a while.
I don't think anyone understood how traumatic an event a coop fire could be. It is. I can't imagine a house fire. God bless, and good luck.