Musnad Ahmad 30:604

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from al-Zuhri, who said: Abu Salamah informed me, from Abu Hurayrah, from the Prophet, peace and blessings of Allah be upon him, who said: "The Fire complained to its Lord and said: 'O Lord, parts of me are consuming other parts, so grant me relief.' So He permitted it two breaths every year: the most intense cold you find is from the *zamharir* (intense cold) of Hell, and the most intense heat you find is from the heat of Hell."