The Sandhya(prayer at dawn and dusk) preached by the Ancient Brahma to his pupils has 21 hymns that makes a man more pious and makes him the god. The same prayer is given in Sanskar Vidhi, a book written by Swami Dayanand Saraswati in the form of Brahma Yagya. The following hymn is given in it -
In this hymn seven types of Heavens are declared as Bhuh, Bhuvah, Swah, Mahah, Janah, Tapah and Satyam planets. These seven planets are seven Heavens. The Earth is called Bhuh planet. So it is proved that the earth is the Heaven of first place from seven Heavens. Similarly to its superior there are six more heavens. The Heaven is the place where the sorrow is very less and pleasure and happiness is in excess.
Just like these seven Heavens there are seven Hells below Bhuh Planet or the Earth - Atal, Vital, Rasaatal and Kumbhipaak etc. There is very less light of knowledge and light of sun here as well. That is why in these planets sorrow is found in access. We can think when the nature, weapons or instruments of Science, all thinks made by human, human behavior, society, planets and stars etc are considered, and with it worldly sorrow and pleasures etc when give us anxiety, sorrow, it is because of only lack of true knowledge. If a human being has the true knowledge about everything, natural disasters, family incidents as well as social incidents on which he/she has no control, will not give him/her any sorrow or problem.
Means where the light of knowledge is lesser, problems, fiction, sorrow is more and more. Kumbhipaak hell is the most sorrowful Hell. Where family incident, natural incidents and social incidents all are not bearable. And in lack of true knowledge the incidents become more unbearable.
In 40th Chapter in Yajurveda, there is a hymn that is preached by the supreme power himself that say -
ॐ अन्धन्तमः प्रविशन्ति येSविद्या मुपासते .... ।
Means the persons enters to the darker planets (Hell) to take birth after death from here, who ignores the knowledge and who acts for only Avidya (Ignorance, Action and devotion is called Avidya because in it there is no special need of knowledge). Here in this Hymn an existence of Hell is indicated.
In the same hymn it is said forth who ignores Avidya and have faith in only knowledge (book worm) enters to more dark planets of knowledge and sun light. Means they, after death from the earth, moves to more low Hell than the above.
But there is only one method of saving us from the Hell as in Yajurveda in just next hymn the god himself said - After understanding well Knowledge, Action as well as Devotion well, we can win death by Action and Devotion and we move to Salvation with the help of the Knowledge.