Protrude the tongue a little away from the lips. Fold the tongue like a tube. Draw in the air through the mouth with the hissing sound Si. Retain the breath as long as you can hold on with comfort. Then exhale slowly through both nostrils. Practise this daily again and again in the morning from 15 to 30 times. You can do this either on Padmasana, Siddhasana, Vajrasana or even when you stand or walk.This Pranayama purifies the blood. It quenches thirst and appeases hunger. It cools the system. It destroys Gulma (chronic dyspepsia), Pleeha, inflammation of various chronic diseases, fever, consumption, indigestion, bilious disorders, phlegm, the bad effects of poison, snake-bite, etc. When you are caught up in a jungle or any place where you cannot get water, if you feel thirsty, practise this Pranayama. You will be at once relieved of thirst. He who practises this Pranayama regularly, will not be affected by the bite of serpents and scorpions. Sitali Kumbhaka is an imitation of the respiration of a serpent. The practitioner gets the power of casting his skin and enduring the privation of air, water and food. He becomes a proof against all sorts of inflammations and fever.