The common idea of hell is fire, brimstone, eternal suffering and the Devil as its master and host. This image of suffering and damnation goes back to the Kingdom of Hades in Roman/Greek mythology and even as far the Underworld in the time of the pharaohs. The image of fire and brimstone comes from multiple verses in the Bible.
Anyway NYC today was hell on earth with fire and brimstone (heat of 102°F and 100% humidity), suffering (dangerous conditions for people with asthma or other respiratory ailments, small children and the elderly), but no devil other than the heat and humidity.
Taking the subway -- other than taking the bus system -- was no easy task. It was like descending to the guts of hell. At least most subway cars -- and buses for that matter -- have a working air conditioning system. Of course, air conditioning doesn't mean anything when the subway car or bus is crowded due to the increased production of CO2 and body heat.
Summer time is this city can be brutally hot and humid. Yet the only thing worse than the heat and humidity is the smell of sweat on oneself and others.
