Foods stay frozen longer if the freezer remains unopened, is full, is in a cool place and is well insulated. Usually food in a loaded freezer will stay frozen for two to four days, depending on its size. A half-filled freezer will keep food frozen only about 24 hours. Cover the freezer with blankets, keeping them away from the compressor, to help hold the cold.
Anxiety and depression indices also point to the likelihood of an adverse effect on mental health from shift work and long working hours. Nevertheless it must be remembered that, by and large, shift workers are a self selected population.
Shift work was once characteristic primarily of the manufacturing industry, where it has a clear effect of increasing the use that can be made of capital equipment and allows for up to three times the production compared to just a day shift. It contrasts with the use of overtime to increase production at the margin.