Trapping atoms
Laser cooling is limited to refrigerating the atom gas to temperatures near a millionth of a degree above absolute zero. So, just like your body sweats to regulate its temperature, we use evaporative cooling to reach the lowest temperature possible in our experiment.
After laser cooling, we turn off all of the light and the atoms are trapped using magnets. We force the highest energy atoms to leave, and the atoms left behind become colder. We don't need to worry about getting frostbite since all of this happens inside an insulating vacuum container.
We cool these atoms to such low temperatures so that their behavior is dominated by quantum effects.