Kevin,

Basically, heat will relax muscles and cold or ice will help take down inflammation. I am guessing that your friends mean alternating. I have to do that with my neck and back sometimes. The only thing is, if using ice or cold, only do it for about 20 minutes at a time. Has your dad seen a spine doc? Since you said it is pretty severe my suggestion would be to see one; preferrably a spinal pain management doc if your dad doesn't get any better or any relief. Oops, forgot to add. I am having problems with my shoulders from having had fusions. Yesterday, the Ortho doc and PT both said...ice on the shoulder itself and heat on the trapezius. So, there ya go. One to take down inflammation and the other to help loosen up the muscles.