The MTA is checking the temperatures of workers at 71 locations — an expansion of a testing program to look for a key symptom of the coronavirus, which has devastated the agency.

More than 3,500 workers a day are being checked by the so-called temperature brigade using contactless thermometers, and anyone with a fever of more than 100.4 degrees Fahrenheit is sent home, the MTA said. The program began at a handful of locations in March.

The number of workers quarantined because of COVID-19 has dropped nearly 50% from a peak of 3,226, according to the agency, which said it finds fevers in about 1 out of every 1,000 employees who are checked.

As of Friday, 84 MTA employees had died of COVID-19.

“Our goal is to provide the optimal level of protection for our heroic employees, as well as extend that assurance to essential workers riding our trains and buses,” MTA Chief Safety Officer Patrick Warren said. “We are heading toward having our Temperature Brigade Program test our entire workforce periodically prior to their reporting to work, an important measure to prevent the spread of COVID-19.”

The MTA said its frontline workers who show COVID-19 symptoms can get prioritized testing for the bug at 52 Northwell Health urgent care centers.