The platforms are like a free sauna. (Photo by Arin Sang-urai/Improv Everywhere)

Every summer the subway platforms become hotter, because that is how seasons and temperatures work. Sometimes it feels very hot down there, but sometimes it's so hot outside that it feels cooler down there, and sometimes when that subway wind comes blowing through the station, there's nowhere else you'd rather be.

Our unscientific research has shown that usually platforms hit around 90-degrees in the summer, but WNYC surveyed 103 of them this week and discovered what may be the most "dangerously hot" one in town: the Brooklyn Bridge-City Hall 4/5/6 platform hit 106.6 degrees! This was last night at around 7 p.m. They also found "the most pleasant platform was 5th Ave-59th St. on the N-Q-R, at 68 degrees. The median was 84.2 degrees, a tad cooler than the official air temperature of 89 degrees at 6 p.m."

In the past when we've the MTA asked about cooling the subway platforms, we were told that just isn't going to happen, but some of them are indeed cooler than others—"there are coolers connected to Grand Central Terminal at the Grand Central Station and an air tempering system at the new South Ferry station. The future stations for Second Avenue and the No 7 extension will also have air tempering systems." Why can't all platforms be as chill? The MTA's Adam Lisberg explained to us this morning, "The platforms are hot. You'll notice ‎the trains have air conditioning. But making the trains cooler requires pumping the hot air out... and [the hot air] ends up in the stations."

Additionally, WNYC notes that a venting system "would require MTA control over what's directly above the station—which often isn't the case." Your best bet is bringing a paper hand fan down there with you. Or maybe a nice cold Heineken? Or maybe just avoid the hottest stations in this map: