The heat resistor of an incandescent light bulb does not burn out, because it is covered by glass that prevents oxygen to interact with it. Burning is a process that always requires oxygen. Usually, the glass case of an incandescent light bulb is also filled with elements such as nitrogen and argon. These elements prevent the filament from evaporating into gas.

The hottest type of incandescent light bulb is the halogen bulb. Its glass casing contains a special glass that makes it possible for the filament to reach a high heat. A filament that burns at a high heat also produces a lot of light. Incandescent light bulbs should never be covered with cloth or any other material because their glass casings can warm up and set the material on fire. This is especially true with halogen bulbs.


Incandescent light bulbs.

Because incandescent light bulbs produce more heat than light, they have mostly been replaced with more useful types of lamps, such as fluorescent lamps and led lamps. A fluorescent lamp consists of a glass tube that is filled with mercury and covered with a fluorescent material. When the fluorescent lamp is connected into a closed circuit, the mercury gas begins to produce invisible ultraviolet radiation. The fluorescent material on the lamp's surface transforms this radiation into visible light.

If a fluorescent lamp begins to flicker, it must be replaced. A flickering fluorescent lamp can even cause a fire hazard. 


Because incandescent light bulbs produce more heat than light, they have largely been replaced with led lamps and fluorescent lamps.