Yup, what everyone else said....
Increase temps will never kill off ick, just speed the process up a bit.
As far as it disappearing, that's a normal part of the ick life cycle. Cysts hatch out, free swimming stage swims around for a couple of days looking for hosts, free swimmers then attach to fish, then several days later they grow large enough that they are visable on the fish (the white spots), and a couple of days later they drop off >>> and the cycle repeats.
At this point you should consider the tank infected. For now, I would suggest feeding well, doing all you can do to minimize stress (so probably do nothing), and start doing some serious reading on ick and what your options are.
In short, you will either "manage" the ick, or "eradicate" it. Managment approaches include; feeding garlic, using cleaner shrimp/fish, UV serilization, reef safe ick "cures", and generally keeping stress minimal and feeding plentiful. Eradication involves removing and treating ALL the fish with Hyposalinity OR copper, while leaving the display fallow for at least 6-8 weeks. Both approaches have their risks and benifits. You'll have to make the call on what to do. (there should be a good amount of info in the "disease treatment" forum on RC, IMO that's a good place to start reading)