What does those spots look like?? If ich, the spots should be like salt grains, raised & crisp. They also should fall off after a few days (to be replaced by other spots).
I actually doubt you are dealing with ich here. A temp of 84 is not high enough to kill ich, and if you havn't seen any new spots on Whitey or the other golds, you are prob dealing with something else. A good close up pic might be helpful. <Definitive diagnosis will need a wet mount of the spot under microscope.>
If the spots are rounded, but not fuzzy, and bigger than 2mm, and if you see some of the spots fusing together, it is likely a virus. (The red veining also points to that.) There is an extensive thread at the GAB about these mysterious white spots on goldies tails. The consensus is that this is a variant of Carp Pox or lymphocystis.
There is also some talk of a Herpes virus epidemic in Goldies in the UK & US.
Goldfish virus going undetected | Practical Fishkeeping magazine
Unfortunately, there is no cure for these viral diseases. Increasing temp apparently can help the fish recover (observation that often the spots disappear over summer). The best thing to do is to keep the temp up in the high 70's or low 80's for 3-6 months & hope the fish recover.
I've had an outbreak of something like this over the summer. I've managed to get rid of all the spots (except for one) with just the high temp over the course of 4-6 weeks. I've lost 2 fish since - and they showed no spots or any other signs (although they are over 5 years old, so might be old age.) The only consolation is that once they recover form the virus, they should be immune to future attacks.