Jack Klein takes heat readings, gives fans to overheated passengers and lugs big jugs of water into the stationsOn a recent August day in the subterranean furnace of New York City’s subway, one bearded, curly haired man was studying his phone for different reasons than the other wilting passengers – to track the soaring temperatures and ponder how underground train stations can cool down in an era of climate crisis.Jack Klein, a 31-year-old construction site manager, has in the past two years taken it upon himself to become a sort of guerrilla subway heat operative, sticking teardrop-shaped thermometers to steel beams in seven of the hottest Manhattan stations and posting social media videos of the hades-like summer temperatures that commuters have to endure. Continue reading...