Sounds like he may have a protruding disk. I have 3-4 in my back/spine area and they can be the most painful thing in the world. If I had had access to a gun when I fell off my deck a few years ago I would have been very very very tempted to use it. Childbirth has nothing in disk pain. My C-6 nerve was impinged and the pain was horrible.
For disk injuries the only miracle is to start a Medrol pack, steroids. The patient takes the first line of pills the first day, the next line the next day, etc...until the last day they only have 1 pill. By the second day I was pain free and by the last day I felt totally wonderful. I did gain about 100 lbs within the next few months and the doc said it was from the steroids but I felt so much better and was able to live again.
I would say he might make his appointment with a doc that understands disks and what to look for. The docs at the ER just kept giving me pain shots and telling me I was just a hypochondriac and that EVERY time I went to the ER I was in the MOST pain I had ever felt....I was in the most pain I had ever felt. Once I got in MRI of my neck and back they saw where the nerve was impinged and how messed up my back was. I have little pain from it now if I take care of myself. I did not have the means to have the surgery they wanted to schedule me for the next day.
I use ice on the painful areas. It kills the pain, 10 on and 10 off. I do stretches when at all possible, door push-ups, putting a pillow under my chin and pushing down, if I can lay flat I put a rolled up towel under my neck and arms out to my sides, knees bent and laying as far out to the side as possible, kind of like a squashed frog face up....lol. It helps if he can get totally relaxed so his muscles will be easier to relax. There are so many nerves going along the spine and the tightness in the muscles will irritate them even more and cause more pain.
If heat makes it feel better, a LOT better, like nearly no pain until the muscles start tightening up then it is probably a pulled muscle and ice may not help that very much.