From daily Metro rider ieva:
I've reported this to Metro via their Web site as well.
This morning at about 9:30 on the Orange Line, in a crowded car (train ahead had offloaded), with no discernible air conditioning on, the riders determined it was sufficient to be called an "emergency" to ask the driver for air.
One person pushed the red emergency button, the red light came on, and ... NOTHING happened.
The driver did not respond.
The red light stayed on.
No response, nothing.
When there was no response, nobody was actually too surprised. We knew if it had been a real emergency we could've gotten word to the driver since we were in the first car.
After, everybody pretty much went back to their reading, etc.
Here's what Metro says about how to use the intercoms:
To report an unusual situation to the train operator, use the intercom at either end of the car.
■ Push and hold the red button and speak into the intercom. To hear responses from the train operator, release the red button.
■ Report the rail car number that’s on the front of the intercom. Describe the problem clearly and briefly.
■ Wait for instructions from the train operator.