This firefighter's conversation with Tegan McCall may have only been about one minute long, but its emotional impact will last a lifetime.

Firefighter Lt. Mike Rheault was responding to a call at an apartment building in Manchester, New Hampshire last month when three floors of smoke alarms all started going off at once.

As Rheault was checking out the building, he saw a young boy with cerebral palsy standing in the doorway of an apartment.

When Rheault noticed that the nonverbal youngster "looked like he wanted to say something," the firefighter intuitively asked Tegan if he knew sign language.

Rheault then proceeded to greet the boy in American Sign Language and introduce himself as Mike.

"And Tegan is just standing there like, ‘Oh my God, someone is signing to me,'" Tegan's mother Amy told WMUR.

Amy quickly pulled out her phone and started recording the heartwarming exchange. After Tegan signed his own name, Rheault taught him the sign for "fireman" and gave the boy a high-five before leaving the hallway.

The @ManchesterFD responded to our building tonight when 3 floors of alarms were going off. Firefighter Mike noticed Tegan not speaking and asked if he knew sign language right before I recorded this. Thank you Fireman Mike and Manch FD ❤️ @mhtinformation pic.twitter.com/aAv9wM3cno

— Amy McCall (@amyjomccall) February 1, 2019

The @ManchesterFD responded to our building tonight when 3 floors of alarms were going off. Firefighter Mike noticed Tegan not speaking and asked if he knew sign language right before I recorded this. Thank you Fireman Mike and Manch FD ❤️ @mhtinformation pic.twitter.com/aAv9wM3cno

Rheault says that he became fluent in sign language during his childhood because both of his parents were deaf. Over the course of his career as a fireman, he says that it has helped him with almost a dozen different encounters on the job – including Tegan.

"[Tegan's] not going to forget it," said Amy. "I'm not going to forget it."

The video of the emotional conversation has been viewed thousands of times since Amy published it to Twitter.

Days after the video was posted, the McCalls were also delighted to receive a fireman's hat courtesy of Rheault and the Manchester Fire Department.

Tegan is really enjoying his new Fire Chief hat from the @ManchesterFD and Lieutenant Mike Rheault ☺️ pic.twitter.com/R8whNpOz3b

— Amy McCall (@amyjomccall) February 1, 2019

Tegan is really enjoying his new Fire Chief hat from the @ManchesterFD and Lieutenant Mike Rheault ☺️ pic.twitter.com/R8whNpOz3b

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