The concept of Jahannam, or Hell, in Islamic tradition, is primarily associated with intense heat and fire. There isn't any mention of a "cold part" within the descriptions of Jahannam.
The Quran and Hadith (sayings and traditions of the Prophet Muhammad) emphasize the torment of Jahannam as being characterized by scorching flames, boiling water, and intense heat. This is further supported by various interpretations and commentaries on these texts.
For example, the Quran states:
"Indeed, those who disbelieve in Our verses - We will surely cast them into a Fire. Every time their skins are cooked through, We will replace them with new skins, so they may taste the punishment. Indeed, Allah is Powerful and Wise." (Quran 4:56)
This verse highlights the intense heat and pain that awaits those who reject God's message.
Therefore, the idea of a "cold part" in Jahannam is not supported by Islamic teachings.
