There are variations in the degrees of heat in Hell, and in the levels of punishment which Allah (swt) has prepared for its inhabitants; there is not just one level.
As Allah says:
“Verily the hypocrites will be in the lowest depths [grade] of the Fire” (4:145)
It is said that both Paradise and Hell have different levels; the lower the level in Hell, the greater the intensity of the heat. The hypocrites will suffer the worst punishment, and so they will be in the lowest level of Hell.
Allah (swt) refers to the levels of Paradise and Hell in the Qur’an:
“For all there will be degrees [or ranks] according to what they did” (6:132)
“Is then one who follows [seeks] the good pleasure of Allah like the one who draws on himself the Wrath of Allah? His abode is Hell – and worst, indeed, is that destination! They are in varying grades with Allah, and Allah is All-Seer of what they do”. (3:162-3)
‘Abdur-Rahmaan ibn Zayd ibn Aslam said, “The levels of paradise go up and the levels of Hell go down” [Ibn Rajab, at-Takhweef min an-Naar, p.5]. It was reported from some of the Salaf that the sinners amongst the monotheists who enter Hell would be in the first level, the Jews would be in the second level, the Christians in the third level, the Sabians in the fourth level, the Magians in the fifth level, the polytheist Arabs in the sixth level and the hypocrites in the seventh level (1) Some books give names to these levels: the first is called Jahanam, the second Ladhaa, the third al-Hutamah, the fourth as-Sa’eer, the fifth Saqar, the sixth al-Jaheem, and the seventh al-Hawiyah.
There is no proof for this division of the inhabitants of Hell or the names that have been attributed to the various levels. The truth is that all of these names – Jahanam, Ladhaa, al-Hutamah, etc – are alternative names by which Hell in its entirety is known, and they are not applied to one part or another of it. It is also known that people will be placed in different levels of Hell according to the extent of their kufr and sins.