The hottest....

Bukhari (54:487) - Someone asked, "O Allah's Apostle This (ordinary) fire would have been sufficient (to torture the unbelievers)," Allah's Apostle said, "The (Hell) Fire has 69 parts more than the ordinary (worldly) fire, each part is as hot as this (worldly) fire." In other words, ordinary fire isn't hot enough to torture non-Muslims. Therefore the fire in Hell is 69 times hotter.