Have you ever sat around a campfire? Felt its warmth on your skin and watched the flames dance? They flicker up and down, keeping us warm and lighting up the night. We love the roar and crackle of a blazing fire.

Fire is useful and accompanies us almost every day. Fires produce heat to warm our homes. We use fire to cook, bake, roast, or grill food. By firelight, we can see even when it’s dark. Fire fascinates us, and we enjoy it when we have it under control.

But fire is also dangerous. It can cause extensive damage in a short time. It can endanger and take the lives of people and animals. When it burns out of control, it destroys homes and forests, factories and vehicles. It can melt stone and steel. It can spread quickly. Sometimes it takes days or even weeks for fires in nature to burn out. Fire is much more powerful than we are. That is why we are afraid of fire.

But how does fire start? What actually happens when something burns? How does a fire go out?

First of all, a fire can only start if there is something combustible. We usually use wood, coal, oil or natural gas to light a fire.

In the next pictures, you can see the firebox of a wood-burning stove. Soon, there will be a fire burning here. Several pieces of wood have been stacked up. Underneath are some cardboard, kindling and a firelighter. The fire is then lit.

Ignition means that the fuel gets so hot that it catches fire by itself. Here’s how it works in a wood-burning stove: the firelighter is lit with a match. Then the cardboard and kindling start to burn. Soon the flames grow larger and hotter. Eventually, the larger logs catch fire too. This requires a temperature of about 280 to 340°C. This is known as the ignition temperature. It varies greatly: a match ignites at just 80°C, newspaper at 175°C, while engine oil needs about 500°C. Burning wood produces smoke because of the moisture still in the wood. The moisture evaporates. Smoke also contains carbon monoxide and carbon dioxide, as well as soot. Burning other fuels also produces smoke and exhaust gases.

The fire first warms the air in the combustion chamber, then the stove itself. The stove, in turn, transfers its heat to the air in the room. Before long, the room is nice and warm. Some of the warm air in the stove rises up through the flue and chimney. That’s a good thing, because fresh air then has to flow into the combustion chamber to replace it. Air contains oxygen, which the fire needs to keep burning. To make sure there is always enough oxygen in the combustion chamber, stove manufacturers have fitted small openings beneath it. You can open or close them to regulate the oxygen supply.

You can also observe the effect of oxygen by repeating the experiment shown in the pictures above:

Fire burns when three things are present: fuel, a high temperature, and oxygen. If even one of these is missing, the fire goes out. Knowing this makes it easy to control a fire.

Look at the picture on the left below. The temperature in the wood-burning stove is still high. There is oxygen too, but there is no fuel. If more wood is not added soon, the fire will go out. So the easiest way to control a fire is to remove fuel or add more.

You can also put out a fire by lowering its temperature, for example by spraying it with water. That’s what firefighters do when they extinguish a fire. You can also deprive a fire of oxygen by reducing the airflow or, for example, shoveling sand over the fuel.