Leg pain can be caused by various conditions, including musculoskeletal, vascular, and neurologic. Accurate diagnosis requires a combination of clinical history, physical exam, and/or imaging tests. Given the severity and frequency of your wife's pain, it is recommended that she consult with her doctor as soon as possible. In the meantime, this symptom checker can help narrow down possible causes: https://familydoctor.org/symptom/leg-problems/
Leg pain can be quite bothersome and we are sorry that you are suffering with this. We recommend that your wife see her doctor to discuss the origin of the pain. Here is another link to consider for information as well as Chin_C's. https://www.mayoclinic.org/symptoms/leg-pain/basics/causes/sym-20050784 She could have something involving wear and tear of joints or arthritis since it seems to improve with cold and hot packs but because there is a wide variety of things it could possibly be, a full evaluation is essential. Something like peripheral artery disease for example needs to be diagnosed sooner rather than later. Does something like Tylenol or ibuprofen improve the pain as well?