The oil poured in to the head is allowed to remain there for a certain period, and this procedure is called as Shiro Vasti. To be more precise , a special hat, preferably made of leather is fixed around the head just above the ear and eyebrow, and it's made leak proof. On to this positioned hat lukewarm oil is poured, and is allowed to remain there for a prescribed period. This therapeutic procedure of snehana to the head is referred as shiro vasti . This is then followed by shiroabhyanga.