Why do i get extreme heat at the back of my neck ? before that i started having insomnia too, are those two things related ?.

Anxiety or else: Severe anxiety can cause symptoms such as sleeping difficulties, breathing difficulties, blushing in face and neck, feeling hot (not related to room temperature), sweating, nausea, among other symptoms. A physician should rule out other causes such as high blood pressure, or hormonal imbalances. If not other medical reasons are found these symptoms could be related to stress/anxiety.