huh, so my dad had back problems his entire life. he trained me to put cold on my back if i hurt it. basically, if there's a pinched nerve, the cold reduces the inflammation. eases the pressure. whereas heat expands everything, and could (doesn't always) increase the pinch on the nerve or cause a spasm.

and y'know, what you're taught as a kid is what you think is normal. has putting heat on your back ever caused it to get worse? more i think about it the more that sounds bullshit to me.