Body temperature drops

My Spouse’s condition-

When resting(sitting down, etc.) she will become very cold having the inability to warm up. She says that it feels like her insides are freezing i.e. bones.
This has bothered her as well has been occurring for 4 to 6 moths. We do not know where to turn, through searching we have found no relief or answers. She has brought this information to her doctor’s attention on numerous occasions. Her doctor provided no answer, he recommended getting a small dog(lap dog) which for me was not a sufficient solution.She does ail from Osteoarthritis and chronic pain syndrome in her lower back.She is only 37. She does take some medications regularly for pain and arthritis and has her blood-work evaluated every other month. We are both in bad shape due to chronic illness as well permanent damage from an auto accident so we have not had the ability to exercise for a few years. I ask for help if there is anyone out there who may have an educated guess to what the cause maybe as well what medical attention she should pursue beyond her primary physician.