Im not sure where the OP got the impression that Temp HP from different sources stack, or where the quote above got the impression that this is how things worked. This is the text from Combat section of PHB (Page 294)
According to the PHB, you don't add up all your Temp HPs from all sources...but what counts as a separate source?
This is day 1 basics I thought everyone understood and had been the status quo for years now.
For example: if a PC wearing the gauntlets triggers their effect, he gets 2 THP. If they work the first way- if each triggering event is the "source"- the wearer will not be able to trigger the gauntlets' effect and gain THP until he loses at least 1 of the 2 he gained the first time.
And then you look at the number of posts and how long they have been around. There was no "Hi, Im new to the game here".Damn, it's almost like new people join this hobby every now and then.
WotC needs to stop letting that happen...
The rules compendium is far more clear on this issue, abandoning the "Source" language entirely. You now only gain the highest amount of temporary HP. So if you have 5 temp HP and a power gives you 2, you still only have 5. At the same time, if you had 2 temp HP and a power gave you 5, you would now have 5 temporary HP and not 2.
Temporary HP never stack (though there may be an exception somewhere).
And then you look at the number of posts and how long they have been around. There was no "Hi, Im new to the game here".
Each time you gain thp, it is a new source.
that's not what I was suggesting at all, since that would clearly run afoul of the rules in the PHB.And for the love of Kord, don't even suggest that they intended you would have to track what power or item granted you thp. "Oh, I've got 3 thp from curse, 2 from gloves, 4 from the cleric... I got hit for 5? Okay, 2 from gloves and 3 from cleric, that leaves me with 3 from curse and 1 from cleric, so I can gain 2 more if I hit next turn." No. No no no no no.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.