Since the cereals are bad conductors of heat there is no problem of heating due to the transmission of heat from the external environment. The cereals, absorbing the heat very slowly, can remain long cold even in the presence of high external temperatures (and vice versa). Moreover, thanks to their good quality of thermal insulation, there is no heating problem even in the case of steel silos which are known to have a very high thermal conductivity. In this case a heating can occur on a small peripheral layer in contact with the silo, but only after a long storage period.