What Could Cause Extreme Temperature Sensitivity And Burning Sensations, And How Can It Be Managed Effectively?

Hello , My sister has been sick for about 2 years, when she is subjected to any temperature over 65 degrees she will start having an extreme burning sensation in the area of her right back and will start shivering due to feeling very cold. The odd thing is that her front side feels cool to the touch but her back get so hot you can feel the heat coming off her back before even touching her. She has been to the Mayo Clinic and the Cleveland Clinic as well as around 30 different specialists and who none gave a diagnosis but prescribed a lot of different medications which did not help and in some cases made the sensations worse. She is also malnourished due to everything she eats makes her stomach acid go crazy causing extreme acid indigestion. She has been so miserable for so long she is beginning to worry me with talking about suicide because she says I cannot live like this forever . The doctors have been calling it idiopathic since they cannot make her better. I would welcome any ideas you may have to make her life even a little more tolerable. Please help