Cooling Breath
Air drawn between the teeth leaves a coolness in the mouth. Tradition calls it "cooling", but measurement doesn't bear that out — we write both.
5 min read
Close your teeth lightly together and part your lips. Draw air slowly through that narrow gap for four seconds. Then close your mouth and breathe out through the nose over six seconds.
The sound happens only on the inhale: a soft hiss. The exhale is silent.
What happens
When air passes through a narrow gap, the inhale slows by itself — you get a long inhale without having to force it.
Second, as the air passes through your wet mouth there is evaporation, and that leaves a clear coolness. You feel it on your teeth and on your tongue.
The "cooling" question
The classical texts describe this technique as cooling. In a study of seventeen people, body temperature was measured and it did not drop; it rose slightly.
So the coolness you feel in your mouth is a real sensation, but it isn't cooling your body. We write it that way both in the app and on the site: the sentence "it cools the body" appears nowhere.
That it feels good on a hot day or when you are angry may come from that sensation and from the slowed breathing. We have no more than a single study with a small number of participants.
How to do it
Close your teeth lightly — don't clench, just let them touch. Part your lips as if smiling, leaving a thin gap between the teeth.
Draw air slowly through that gap for four seconds. You'll hear a hiss.
Close your mouth and breathe out through the nose for six seconds.
The version with the tongue
If you can curl your tongue into a tube and put its tip out between your lips, you can do the same thing with the tongue. Because the gap is narrower, the coolness feels a little stronger — classically called Sitali.
Not everyone's tongue curls; that is inherited. If yours doesn't, don't worry about it: the version with the teeth is the same technique, and it is the one the app is built around.
Common mistakes
Drawing the air in fast. Drawing fast dries the throat and brings on a cough. Draw slowly.
Clenching the teeth. Touching is enough; keep your jaw loose.
Breathing out through the mouth. The exhale is always through the nose, mouth closed.
Doing it in very cold air. Don't do it outdoors in winter or in front of an air conditioner.
How the app measures it
This technique reverses the usual arrangement in the app: the noise is on the inhale and the exhale is silent.
In the other techniques the exhale is strong and the inhale is low. Here it is exactly the other way round, so the app is lenient on the exhale and takes its real measurement from the hiss of the inhale.
This technique's thresholds haven't yet been measured against real recordings — it is running on initial values. If you turned audio sample sharing on, the sessions you do help this setting settle directly.
Who should take care
If you have asthma or are sensitive to cold, be careful: cold, dry air can irritate the airways. The app shows this warning before the session.
When your throat dries out, take a break and drink some water.
Sources
- Hatha Yoga Pradipika (15th century, chapter 2) — verse 54 describes the version with the teeth, verses 57-58 the one with the tongue.
- Telles et al. (2020), Medical Science Monitor Basic Research — body temperature, oxygen consumption and carbon dioxide output measured in seventeen people; temperature did not drop. PubMed