When steaming, the cook usually takes care to keep the lid tight on the pot and the heat high, to make sure that the pot atmosphere is saturated with vapor. However steaming can also be done at reduced temperatures and therefore more gently. Water at a 180°F/80°C simmer in a covered pot will keep the pot atmosphere around 180° as well, and leave the outer portions of the meat less overdone. In China, some dishes are steamed in open pots, where the water vapor mixes with ambient air and the temperature is well below the boil. Commercial convection steamers can produce saturated vapor all the way from body temperature to the boil. They make it possible for restaurant cooks to prepare moist meats and fish with very little attention and keep them at serving temperature until needed.