I'd say that a good hot tub would do the trick. Everyone is different as to what temperature works better--hot or cold?
Here's the facts: Hot temperatures warm your muscles up for soon physical activity in which you'll need your back; for example, many baseball players have to heat up their arm directly before a game as opposed to icing their arm, and here's the reason why: Cold temperatures heal the muscles, ligaments, tendons, and so forth much faster than warm temperatures, but not if you need to soon be off to work. You'll need a few hours before any physical activity after you ice your back.
But don't forget that icing it heals it faster than heating it, but only if you have time to spare. I certainly hope I was of some help.
Patrick