This question came up when discussing the healing effect from the Gloves of Soul Catching. The text for this legendary item states:
After making a successful unarmed strike while wearing these gloves, you can use the gloves to deal an extra 2d10 force damage to the target, and you regain a number of hit points equal to the force damage dealt. Alternatively, instead of regaining hit points in this way, you can choose to gain advantage on one attack roll, ability check, or saving throw you make before the end of your next turn.
So, to put it shortly, you deal force damage to the target of an unarmed strike, then regain health equal to the amount of force damage dealt. But what if that target was yourself?
In any situation, this wouldn't mean much. You would take the force damage and recover this exact same damage. If you had temporary health is where it gets tricky. I have found no rule text or anything else preventing this healing effect from working when damage is dealt to temporary hitpoints, so it seems to me that hitting yourself with the gloves would effectively get rid of your temporary hit points and convert them into "normal" hit points.
Is this reasoning correct, and so can you effectively convert any temporary hit points into actual healing, with no visible downside? Or is there some rule I'm missing that prevents this interaction?