How Can I Help Someone Who Compulsively Scalds Her Chest With Hot Water For Pain Relief Despite Hospital Warnings?

I m a caregiver for a patient and his wife is same age as me 52 and has stopped drinking about a month ago. She says she had problems with her stomaches and has had gallbladder taken out but still hurts and throws up all time and stays in the tub with hot hot water running on her chest to the point of scalding burns on chest. Peeliing layers . Went to hospital jus got out yest and they said no o more baths like that and she already back in there most night and morning over and over. How can I help her before he s skin falls off. Is it in her head or a habit