What technique does Sheetali/Sheetkavi pranayama use for cooling?

Sheetali or Sheetkavi pranayama is designed specifically to create a cooling effect within the body. This technique involves rolling the tongue into a "U" shape and inhaling air through the mouth, which allows the practitioner to draw in cool air directly. This inhalation method not only cools the air but also helps lower the body temperature, making it especially beneficial during hot weather or after intense physical activity.

The act of rolling the tongue, which is distinctive to this pranayama, is vital as it amplifies the cooling sensation experienced with each inhalation. The air passing over the moist surface of the tongue is cooled before it enters the lungs, allowing for a refreshing intake.

In contrast, the other techniques mentioned in the choices focus on different aspects of breathing and do not specifically aim to create a cooling effect. Deep inhalation through the nose or exhaling through the left nostril focuses more on balancing energy or enhancing breath control, while producing sound during exhalation may promote relaxation or focus but does not provide the cooling properties associated with Sheetali pranayama.