Danielle Day was watching her bridesmaids get their hair and makeup done a few hours before her July 18 wedding when the alert came in.

“I looked at my phone and said, ‘Oh, there’s a structure fire,’” she said. Her four wedding attendants, in various states of updos, sensed what was coming. “My sister tried to hand me a mimosa and said, ‘Here, drink this. You’ll be fine.’”

But Ms. Day, a volunteer firefighter, had already made up her mind about how she would respond to the blaze in Town of Phelps, N.Y., where she lives. “I told them, I’ll make a deal with you. If Zach gets there and it’s nothing, I won’t go. If he gets there and calls in other departments, I’m going.”

She went.

Ms. Day, 35, met Zachary Rey, 26, in 2013, just after she started volunteering at the Oaks Corners Volunteer Fire Company in Oaks Corner, N.Y., with her sister, Patti Day. “Patti brought me there a couple times, and I could see it was a really good group of guys helping out in this small town,” she said. Mr. Rey, 18 at the time, stood out. “I wasn’t sure if he would notice me because of our age difference, but he seemed really mature, like he had an old soul. I loved that about him.”

Months of group hangouts with their fellow volunteers at Denny’s and Dunkin’ Donuts brought them closer, until the summer of 2014, when Ms. Day felt comfortable enough to call Mr. Rey and ask if he wanted to help her decorate Patti’s house for a baby shower.

“It was a spur-of-the-moment thing,” she said. When they arrived at her sister’s house in Geneva, N.Y., though, the door was locked. “So we drove around in my 2004 maroon Grand Am, all through the district we were familiar with as firefighters, and I got him to open up a little. He’s a pretty quiet guy.”

Credit…Brian Ocque

By 2015, they were in love and moving toward building a life together with Ms. Day’s two children from a previous relationship. Her son, Lance, is 14; her daughter, Remedi, is 11.

Though their work at Oaks Corners sometimes overlapped, they spent their days apart at paid jobs, his as a securement specialist at a trucking company and hers at North Seneca Ambulance, where she works in emergency medical services. By 2018 both were also taking on additional responsibilities at Oaks Corners. Mr. Rey became deputy chief and Ms. Day emergency medical services captain.

On Aug. 18, 2018, on their annual camping visit to the Adirondacks, Mr. Rey proposed. Coronavirus did not get in the way of the July 2020 wedding for 100 they planned for their back yard in Town of Phelps, though they hadn’t anticipated the masks and social distancing.

Both were hoping for no fires on July 18. But experience had prepared them in the event one broke out. “We’ve had to drop everything at birthday parties and during holidays,” Ms. Day said. “That’s just how the cookie crumbles.”

So when Mr. Rey barreled off to start battling what turned out to be a two-alarm fire in Town of Phelps at 11 a.m., Ms. Day was not flustered. “I was actually OK with it,” she said. The wedding, to be officiated by their friend Sara VanCamp, who was ordained by the Universal Life Church for the occasion, was set for 4 p.m.

While Mr. Rey supervised putting out the fire inside and Ms. Day handled medical care for firefighters outside, both were mindful they had a schedule to adhere to. Ms. Day left the scene at 1 p.m., and Mr. Rey about 2 p.m. “I was keeping an eye on the time,” he said.

After they said their “I do’s,” they reflected on the events of the day. “We were actually proud that we got to go put out that fire,” Ms. Day said. “Yes, it was our wedding day. But we were able to go and help somebody on their worst day, on our best day.”