Symptoms of an RI include drooling, mucous or bubbles around the nose and mouth, clicking or popping when the snake breathes.

85* isn't really enough to give the snake an RI.

If your snakes are in tubs I would suggest switching to paper towels so you can see any possible mucous smeared around. Also makes for a cleaner environment. You can spot messes faster and such.

I wouldn't leave the snake on damp substrate. That could cause scale rot.

I am not sure on the dosage but baytril is a commonly used antibiotic for RI's.