Ice cools down an acute flare-up by reducing swelling and strain on aching back muscles.
Moist heat, on the other hand, helps reduce muscle spasms. Using both heat and ice intermittently provides relief to a person with back pain. A reusable bottle for hot or ice water, one that not only feels good but looks good, will earn you bonus points with the victim. Now they can go out in public with their water bottle, fashionably. My brother has chronic back pain.