Needless to say, it’s been a wee bit hot out in New York City. As the heat wave finally crests so that temperatures are a cool 80 degrees as I write it, the heat has settled into the city like an unwelcome house guest. It fills every nook and cranny with uncomfortably stale air and the smells of New York in the summer. It is indeed a pity the days can’t be like the nights.

New Yorkers though have a special dread of summer. It’s hot outside, but it’s worse underground. The heat traps of the subway system, made even warmer with the exhaust from subway cars pushing the mercury up higher, create unpleasant rides on a good day. At least, we think, the air conditioned subway cars offer a respite from the warmth. But what if it all goes wrong?

For a while on the site, when summer dawned, I would dive into the history of bringing air conditioners to the subway system. We haven’t yet solved the platform problem (although new deep-bore stations offer climate control), but after three decades of starts and stops, the MTA introduced a fully air conditioned fleet of subway cars by the mid-1980s. The ceiling fans seen in the old rolling stock at the Transit Museum seem simply quaint these days.

Lately, though, certain air conditioners have begun to fail. Most notably, the single-compressor units in the R62A cars — what you might know as the 1 and 6 trains — have been plagued with outages. The problems began in bits and spurts a few years ago, but with the sustained heat, the issue has exploded in a wave of Tweets directed toward @NYCTSubway, and a transit agency that can’t do too much more than acknowledge the problem.

Kate Hinds at WNYC has covered this story tirelessly this summer because she, like the rest of us, is wary of getting into the so-called hot cars. In late July, when she first wrote about the problem, the MTA explained that they field reports via social media, log them and try to figure out when to address them. The R62As are particularly prone to outages. These 30-year-old cars are due up for scheduled maintenance and have one compressor rather than multi-unit HVAC systems which are easier to repair. They’re old; they break.

But the problem has been the repeat offenders. Hinds revisited the story this week, and either the problem is growing or people are paying more attention. The MTA, which still claims only around 12 reports today, has fielded upwards of 30 air conditioner complaints on Twitter each day this week, and may cars are repeat offenders with early reports stretching back to mid July or even early June. Simply put, the problem is not going away.

Again, these issues are two-fold. First, the MTA doesn’t have the leeway to take one car out of service. Due to the way trainsets are coupled, removing one car from service basically torpedoes half of a ten-car train set. If the MTA took all of the problematic cars out of service, it wouldn’t have nearly enough rolling stock for peak hour demand. (By my count, at this point, around 40 or more different 1 and 6 train cars have been flagged for AC outages. I’m sure more hot cars are out there that haven’t been reported yet.) Second, while the MTA acknowledges that the R62As need scheduled maintenance, the SMS process can take nearly two years. These cars aren’t getting fixed overnight.

It’s bad solution to a design problem that isn’t getting fixed any time soon. We’re going to be hearing about hot cars until the R62As all undergo scheduled maintenance, but it would behoove the MTA to be upfront about this. Right now, they’re asking New Yorkers to report hot cars but are essentially saying that we have to keep riding them until the agency can find a solution. Beware then those emptier cars in an otherwise crowded train. It’s going to be hot in there.