The temperature of a light bulb varies depending on its type and usage. Incandescent bulbs emit heat due to the heating of their filaments, with temperatures reaching up to 1,900-2,700 degrees Fahrenheit. Fluorescent bulbs, on the other hand, convert electrical energy into ultraviolet light, which is then emitted as visible light, resulting in lower heat generation. LED bulbs are highly efficient and produce very little heat, typically below 120 degrees Fahrenheit, making them cool to the touch.