It just try to maintain the initial temperature of the food you pour in, the general requirements are boiling water ah what to pour in, because the temperature is relatively high, insulation time is long, so it is possible to put the physical simmering, protein denaturation cooked as long as 60 degrees can be, starch cooked as long as seventy or eighty degrees is enough, daily life in the main food belongs to the two major categories, as long as the insulation long enough time, basically food can be cooked. But the flavor is definitely not as good as using fire