Not really. You would need to move the fish to a hospital tank to treat them.
You really have to try to make sure your fish stay happy and healthy. I would recommend QT for new fish but I don't know where I stand on that anymore...It has not exactly worked for me in the past year or so. A lot of hard work only to have ich in my tank anyways. I personally have found that for my tank, keeping the fish healthy and well fed has worked much better to treat stuff like ich than hypo ever has. I have spoken to a lot of people lately who are taking the same approach. Not suggesting this is for everyone and I think QT is always a good idea but it just has not worked well for me. I have had great success letting my fish fight it off themselves though. After QTing them all for a total of almost 6 months, they still got ich again. After 1 month of feeding very heavily with Tropic Marin vitamins and garlic as well as keeping water quality ideal, no ich for about a month and a half now.
Having said all that, if you ever needed to treat for anything you would need a QT tank. Make sure you do have one just in case.