I'd even suggest a bigger water change up to 50%, and you should also vacuum the gravel, because the parasites fall from the fish when fully developed and build cysts, then they multiply and search for new hosts.
You will already have a lot of them in the gravel, so you can reduce their number by cleaning it. After that put in the salt. A higher temp without salt or medication would only worsen it.
I guess your med contains at least malachite green which is effective against the ick parasites in many cases. You won't see a result immediately though, because it only kills the parasites in their free swimming stage, that means when they are searching for new hosts. Those sitting on the fish will not be affected, you have to wait till they are fully developed and fall off, which may take a few days.
So if you'd like to go on with the med, you need to treat for several days. I hope this is mentioned on the package. It would also be better to leave the lights off cause malachite green is sensible to light and loses its effectiveness.
When you're through with it, try to give them more room to reduce the stress.
Good luck, hope they will get well again! The chances are somewhat smaller if the gills are infected.
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cu,
Gisela
moppel@gismo.owl.de