Bacchus is correct on all counts. Cranking the heat will encourage the parasite to drop off the fish faster to breed in the gravel, where it becomes vulnerable to the copper.
Beware of any -fix -revive -repair medications. As their name suggests they are marketed mainly to people who have no clue what is wrong with their fish and are looking only for something that will 'fix' them.
The main (and only) active ingredient in Melafix is Melaluca or Tea Tree oil. It makes a good antiseptic (not antibiotic) but not much else. Meaning it works much like rubbing alcohol by killing bacteria on open wounds. So if, for instance, your fish got burnt by a heater or bitten, adding melafix to keep the wound clean and prevent infection would be a good thing. But if your fish has ich, a bacterial infection, internal parasites, etc it won't do anything.