I recently inherited a Donjoy Iceman. Basically, an igloo cooler with a water pump that keeps ice water circulating through a pad. I used it on my swollen knee last night (blocked a shin with my knee), wow, I do not know why I did not buy one of these before. Way easier than an ice pack, less messy too. Well worth the $50-60 I see them on ebay for.
Now I just need a hot tub for the opposite effect.