LED bulbs do indeed generate heat as does anything that consumes electricity. The important thing to keep in mind is that LEDs consume a lot less energy than incandescent or halogen bulbs and are much more efficient in how they use that energy versus traditional bulb types.
Thus while LEDs will generate heat, it will be a fraction of that compared to a traditional technology bulb. The ultimate temperature at which the external housing of the LED will operate depend on the room temperature.
So LEDS are safer more efficient and much cheaper to operate than traditional incandescent or halogen bulbs.