BlueMoon, she wasn't like that when I got her. It's definitely not a burn. She's got belly heat and it's not hot enough (90 degrees with a thermostat). Serpent Merchant, she's in a tub with two identical hides, and a water bowl, nothing else. Temps and humidity are spot on. Her setup is the exact same as the rest and all of my others are fine. I'll get some betadine and switch her to paper towels. There's nothing that could cut or scrape. The inside of the tub is smooth. My hides are different, but my therm/hygro (in addition to thermostat) is the same as yours and the bowl is the same type, but a little bigger.
She was soaking when I got her, but the humidity was low (aquarium setup) and she doesn't have mites. I've checked her water, put her on paper for a few days, and looked all over her just in case and she hasn't soaked at all since I've had her. She hasn't eaten for me yet, but it didn't raise any warning flags because she's new and I've had them take a week or two to eat. She's obviously in pain and it hurts my heart that she's hurting and there's nothing I can do but leave her alone.