You do something genuinely kind — give something away, help somebody who can't repay you — and afterwards there's a warm feeling in the chest. Everybody knows it. It has a folk name in English and a technical one in psychology.
The account offered here is mechanical, and it's stated without hedging:
Whenever you practice some spiritual virtue (such as performing a selfless act of mercy, charity or kindness) and resultantly feel a warm sensation in your body, you should understand that the deed and your emotional response are opening Qi channels within your physical body… The Qi is going through blocked channels, opening them, and the warmth you feel is the friction of that passage as the channels open.
Same explanation given elsewhere for the heat in energy practice. Something moving through a narrow place and meeting the sides of it. And the consequence drawn is that ordinary people, with no practice of any kind, are doing channel work without knowing it — "one of the ways in which ordinary people, without any special spiritual practice, help to purify their inner etheric Qi body."
[RESONANCE] Because it takes the least suspicious feeling available to a person — the warmth after a good deed — and puts it in the same category as a sore back during qi-gong. Both are friction. Neither is a reward.
That inverts what the warmth is usually taken to mean. It's normally read as confirmation: you did the right thing, and here is your body agreeing. On this account the warmth isn't the body approving. It's the body being changed, in a place that was previously stuck, and the approval reading is a story laid on top of a mechanical event.
The vault already carries the page: The Warmth After a Good Deed. What the spark adds is where it sits relative to two other things.
Against Forty Sensations, and the Order to Ignore Them: warmth is item two on a list you're told to ignore. So the same sensation is meaningless in a session and diagnostic after an act of charity. Nothing in the corpus draws the line.
Against The Four Immeasurables Are a Qi Protocol: there the emotion is deliberately generated as a tool, and here it arrives unbidden and does the same job. Which raises the question the corpus doesn't ask — whether a manufactured compassion produces the same friction as an unplanned one, and whether the difference would be felt or only believed.
Warmth as confirmation versus warmth as work. If it's confirmation, doing more good deeds should feel steadily better. If it's friction against blockage, it should feel less over time in any area you've cleared — the warmth should fade as the channel opens, and its disappearance would be the real marker.
That's a genuine, checkable prediction, and it cuts against the folk reading hard. Somebody who has given for thirty years should feel less than a beginner does, and would ordinarily read that as having gone cold.
Promotion criterion. Any contemplative tradition that reports the warmth diminishing with practice rather than growing. Christian material on consolation and dryness is the obvious hunting ground, and the desert tradition's insistence that consolation withdraws from the advanced is either a confirmation of this shape or a completely different claim wearing the same clothes.
Next action. Check what the vault already holds on consolation and dryness before going outside for sources.