Assalamu Alaikum Wa Rahmathullahi Wa Barakathuhu
Is it allowed to do wipe off (مسح) on warm plasters since it is not used on a wound but used only during a pain?
الجواب حامدا و مصلیا
If using water is really harmful, it is also correct to do wipe off (مسح) on it without removing. But in a situation where using water is not harmful, it becomes essential to remove the plaster and wash.
Allah knows best.