A fire balloon is a special kind of balloon that is made of paper and can fly up into the sky like a regular balloon. However, it's different from just any balloon because it's filled with hot air. You know how when you blow on a heating vent, hot air comes out? That's what's happening inside the balloon, but there's no vent, just a flame.
The balloon is usually made by taking a piece of paper and stretching it out, then folding it up a certain way to make a basket shape. This basket is what holds the flame. Then, the balloon is attached to a string and it's ready to fly!
The way a fire balloon works is through something called the "hot air balloon effect". As you know, hot air rises because it's less dense than cold air. When the flame heats up the air inside the balloon, that hot air becomes lighter than the air around it and starts to rise. That's what lifts the balloon into the sky!
People have been making fire balloons for a long time - all the way back to ancient China! They would use them for celebrations and special events. Nowadays, some people still make and launch fire balloons as a form of art or just for fun. However, fire balloons can be dangerous if they're not handled safely. If the flame inside the balloon touches something flammable, like a tree or a house, it can cause a fire. So, it's important to be careful and follow the rules when making and launching fire balloons.