What about creating Exxon levels? Like we have ozone.... Today the temperature will be 134 Exxon level 1. Humans can survive 5 minutes at Exxon level 1. Exxon level 4 lowers survival to 30 seconds outside of AC controlled systems.
Na man, lets combine, with a sponsor type plug, "Mythical creature from hell heatwave, brought to you by Shell, Shell, displacing and killing natives for oil since 1921."
Also according to an angry Italians fanfic of hell, its not really that hot there either. Some little bits of it are, mostly revolving around people who were generally assholes in life, and a non-zero number of recently deceased (See the 14th century) popes the author had an axe to grind with.