You should move the sick fish to a quarantine tank if possible.
Since ich infects the whole tank, treat the entire tank. It is not necessary to stress the fish further by moving them.
The reason ich is now showing up on your other fish is due to increasing the life cycle of the parasite. The ich would have shown up regardless of the heat and salt. With this treatment, things get worse before they get better. You will see the ich clear up from these fish and then continue the treatment for 2-3 weeks longer. I agree with Jchillin--go back to your normal PWC
routine and add the salt already dissolved in water all at once--the fish will be fine. Make sure there is enough surface agitation because less oxygen diffuses into warmer water. 86*F is the highest temp you need.