I once had an elderly pt with longstanding problem that she would describe as mostly "coldness" with a bit of numbness. Nil incident before onset, and no obvious aggravating factor. She said that the Sx is constant, moving around and resting have no effect on it.
On examination, I found that her ITB were tight, especially on the symptomatic side. So I did Heat, followed by ITB release. It was painful for her but she got 40% improvement after the first session, and by the end of the 8 sessions she had around 10% left.