It is common practice to reheat several times both breast and formula milk, using methods that do not guarantee the correct temperature such as pots, bottle warmers, microwave ovens. The preparation of milk before administration can be via baby bottles warmers with a set default temperature. Liquid formula can be warmed in hot water up to 35 °C (95 °F), while the milk powder must be added to water at a temperature of 70 °C (158 °F). Breast milk should be administered at room temperature.At an inadequate temperature many beneficial properties of milk, breast milk especially, vanish. Once heated, milk not consumed within half an hour must be discarded to prevent bacteria proliferation. In the absence of single doses, avoid the entire bottle of milk to cool and then be reheat. Health care providers and parents should be aware of these problems, especially when referring to sick and premature babies.