There's one sound that gets a big reaction from kids on a hot day, the sound of an ice-cream truck.
Maria McCartney has been in the mobile ice-cream business since 2005.
"When I was a little girl, I saw an ice-cream truck and knew I wanted to have one someday," McCartney said.
During the hot days of summer, Maria and her daughter drive an ice-cream truck through neighborhoods and parks in Billings.
It's not about making money for this former elementary school teacher. Rather, she wants to preserve the tradition of the neighborhood ice-cream truck.
"Truly my favorite part is to see the kids jumping up and down and they just get so excited. It's great to build a memory for them too. There are not a lot of these ice-cream trucks around anymore. The parents come out barefoot and screaming, ready to buy ice-cream; they remember when they were kids and they saw a truck," she said.
While the treats may be ice-cold, Maria has a warm heart for little faces. Her truck features a donation bucket for kids who don't have money for ice-cream.
"When there are three kids and only two of them have money, I always make sure the third one gets something because I can't drive away and have that third one not have something," she said.