I have been having tooth sensitivity and I had pain when I eat/drink hot or cold food/drink. One day, I went out to eat. I was pretty hungry and I ate hot food without letting it cool first. The food was too hot and my tooth started really aching since then. That was Saturday evening and I continued to have pain until Tuesday morning.
I had root canal on Tuesday. Root canal procedure is not something I wanted to have but I was tired of dealing with tooth sensitivity and I did not want to do extraction, so I reluctantly do it finally. What I found it interesting is that even thought the nerve is gone and I should not be reacting to cold/hot food and drink, I was still sensitive to them and afraid of drinking/eating hot and cold food/drinks.
I have heard of people who lost their arms/legs but they still have pain (at least they feel like they have pain on their arms/legs). I think it is a similar situation and it is also similar to my electromagnetic hypersensitivity condition. Once you are hurt and experience pain, your unconscious will try to guard yourself. My conscious needs to learn that cell phone, EMF, WIFI is not immediate danger and it does not need to overly protective of myself.