Halogen lamps are incandescent lamps filled with highly pressurized inert gas combined with a small amount of halogen gas (bromine or iodine); this lengthens the life of the filament (see ). This leads to a much longer life of halogen lamps than other incandescent lamps. Due to the high pressure and temperature halogen lamps produce, they are relatively small and made out of quartz glass because it has a higher melting point than standard glass. Common uses for halogen lamps are table top heaters.