It is no stretch to say that Lee Mendelowitz, a scientific computation doctoral candidate at the University of Maryland at College Park, knows more than a couple of things about coding and data.

Mendelowitz, 27, writes code as part of his graduate work. And sometimes he does it for fun.

In May, during his daily commute between the U Street and College Park stations, Mendelowitz came up with a plan to let Metro and others know where the hot cars were. In four or five hours, he created a program to track tweets about hot rail cars and an automated Twitter account to send that information to WMATA officials.

“I thought it would be a great data science project to crowdsource these reports and share the results with the public,” he said.

Mendelowitz gathered information from those tweeting the four-digit car number and line color and including the hashtags #wmata and #hotcar.

Then the automated Twitter account he created, @MetroHotCars, tweets the hot rail car number and a link to other reports about the same car to WMATA’s @MetroRailInfo account.

Mendelowitz said he wanted the complaints to have a purpose.

“I hope that the project is useful to WMATA so they can focus on fixing the cars that get reported the most,” Mendelowitz said.

Since he created the program, Mendelowitz has collected almost 500 reports on hot cars and plans to keep his algorithm running through the summer.

For riders like Mark Farrell, the service could provide a way to avoid the kind of sweltering commute he endured during Washington’s recent heat wave.

Farrell, 29, a federal government employee working on IT policy, takes the Metro from the Navy Yard station to McPherson Square. Every day last week, he said he encountered at least one car without air conditioning. On Friday evening, the commute went from bad to worse. He ran into three hot cars in a row. He rode for a while in one before switching again. Finally, the fourth car he rode in had air conditioning.

Farrell said he tweeted the car numbers of the two hot Orange Line cars he avoided.

Based on Mendelowitz’s program, Twitter users reported 122 different cars having problems between July 15 and July 18. Most tweets were sent on Friday and Wednesday evenings between 8 p.m. and 11 p.m. Cars on the Red and Orange lines were mentioned several times.

The number of hot cars reported on Twitter represents approximately 15 percent of the 860 cars WMATA says it operates during rush hour.

Of the cars reported as having air-conditioning problems, 47 were on the 1000 series cars, the oldest models operating in the Metro system. There are 288 cars in this series.

The 5000 car series, which has been operating since 2001, had the most complaints, with 53 different cars reporting problems. Metro currently has 184 cars in the 5000 series.

Caroline Lukas, WMATA’s spokeswoman, said the best way to report a hot car is by using the intercom and letting the train operator know about the malfunction. She said this would allow maintenance staff to troubleshoot while the train is in operation.

She also questioned whether  Twitter usage is the best way to measure Metrorail performance.

“What is hot to one person is not necessarily hot to another, making the definition of a ‘hot car’ an issue,” Lukas said.

She said Metro cars have had difficulty maintaining their cool when temperatures hit 93 degrees and above.

WMATA said the agency is working diligently on addressing hot rail car issues and that the number of cars removed from service because of air-conditioning problems has dropped. According to Lukas, next year a new series of rail cars will replace the old 1000 series railcars, reducing the incidence of hot cars.

“The new 7000 railcars have a different HVAC system that will be better equipped to handle D.C. summers these days,” Lukas said.