Gisele Barreto Fetterman, wife of senator John Fetterman, was spotted fighting a fire at an apartment in east Pittsburgh.
Ms Fetterman was seen, in a video clip since widely shared, with her fellow firefighters at the scene of the fire early on Tuesday in east Pittsburgh, local reports said.
She was seen walking in full gear through the area with her colleagues.
The former second lady of Pennsylvania joined the volunteer Rivers Edge 113 firefighting crew in December. She announced the move on Facebook as well.
"Say hello to Rivers Edge 113 newest member (still lots of work ahead but excited and ready to learn)” she wrote, and thanked “the entire team” for mentoring her. “And please consider supporting your local volunteer fire department.”
This took place just before her husband John Fetterman was sworn in as a senator on 3 January.
Mr Fetterman served as Pennsylvania’s lieutenant governor prior to that.
Meanwhile, on social media, several people commented on the video clip that showed Ms Fetterman in full firefighting gear, doing her job.
One user wrote: “Never underestimate @giselefetterman. She really can do it all.”
Another person gushed: “As if we needed another reason to love @giselefetterman. She’s smart, kind, compassionate and a total #shero!”
“The way @giselefetterman is out fighting fires and saving lives with hair and makeup done is truly so amazing to me. What a fantastic role model,” wrote another person on Twitter.
Another person commented on the video: “Watch the #RadicalRight criticize her for being a volunteer firefighter.”
But there was one section that also criticised her. “The wife of a US Senator joined a volunteer fire department so she could walk around in gear on her phone?” tweeted one.
Ms Fetterman married John Fetterman in 2008. They have three children.