Write the next sentence in the following story.

How to refrigerate foods safely
Avoid packing your refrigerator tightly.
Packing loosely allows the cold air to circulate.
Use an appliance thermometer to monitor the real temperature inside your refrigerator and your freezer.
The refrigerator should be at 40 f (4 c) or below, but above 32 f (0 c). Your freezer should stay at 0 f (- 18 c).