well I just posted a nice long reply and it got lost... so here I go again. two links I have for you. first - good news on the goldfish. looks like he should be ok
Can goldfish tolerate 86 degree Fahrenheit ,as i need to raise temperature for white spot attack? - Yahoo Answers
there was a goldfish girl on here - maybe she will chime in for you.
second here is a great article on ick and the heat thing
Understanding and Treating Ich or White Spot
and an excerpt on the temp - keep it above 85 for 10 days
The second approach is to actually destroy the organism with heat, and can be combined with the salt treatment below, but not with meds. The data I studied (including a report by the Southern Regional Aquaculture Center, which is currently archived here) suggests that most strains of Ich cannot reproduce at temperatures above 85ºF. To use this treatment approach, slowly (no more than 1 or 2 degrees per hour) raise the temperature to 86ºF, while maintaining strong continuous surface agitation to oxygenate the water. This is extremely important because water holds less O2 at higher temperatures. (This is why meds should not be used in conjunction with high temp – most Ich treatment products also reduce oxygen levels. Less available oxygen, combined with the respiration difficulties an infected fish is already faced with, could be fatal.) You can angle powerheads up toward the surface, or lower your water level to get a little extra splash from your filter return. As with any treatment, observe your fish closely for signs of stress (labored breathing, erratic behavior) and reduce the temperature slowly if necessary. (A note to the wary; my Malawi haps and clown loaches endured a temperature of 88ºF for 10 days with apparent ease – I never detected the slightest hint of distress – and the Ich was completely wiped out. One article that I read suggests the temperature be raised to 90ºF!)
good luck!