What are the Correct Temperatures?

What Is the Correct Freezer Temperature?  

Most things that do not have high sugar content are frozen solid at about 20 degrees Fahrenheit. Ice Cream needs to be below about 5 degrees to be solid. The colder the freezer temperature, the longer the food can be stored.
Always use 0 degrees F as a goal. That leaves a good size safety margin. Most reach-in freezers are designed to go down below 5 degrees. Most walk-in freezers are designed to get well below 0 degrees. 

What is the Correct Refrigerator Temperature?

The United States Food and Drug Administration set the maximum refrigerator temperature at 41 Degrees Fahrenheit.
That temperature is the maximum for the actual product being refrigerated. This is often confused for the air temperature. The air temperature may fluctuate but the product temperature must remain at 41 or lower.
The colder the product, the longer it will last. That makes 38 Degrees a more optimum temperature. A unit set at 38 Degrees might come on at 38 Degrees and shut off at 35 Degrees. Temperatures below 35 Degrees require a forced defrost cycle.