<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been feeling hot and cold lately, and I noticed that I have been nailbiting excessively. I also have back pain and I even fainted earlier. Additionally, I noticed that my hands and fingers have been swelling. What could be the problem?  <response>: Based on your symptoms, it sounds like you may have frostbite. It is a condition where the skin and underlying tissues freeze due to exposure to cold temperatures, causing injury and potentially serious complications. I suggest you seek immediate medical attention to prevent further damage. 