Food must be colder than 41 ° F when you put it in the ice. Hold cold foods at 41 ° F or less. Cold food is held at 41 ° F or lower to keep germs from growing. It should be measured for temperature using a probe thermometer at least every four hours.
Microwaves have ‘hot’ spots, and ‘cold’ spots. That is the reason for the rotation, to account for the uneven distribution of the waves that excite the water molecules to heat the food. If the food sat in one position, there would be areas that would be hot, and other areas that would be totally cold.
Microwave and food manufacturers often recommend leaving food to stand for a few minutes after cooking or defrosting. This is important for safety as it helps to even out the temperatures and eliminate hot spots. A good rule of thumb is to leave food to stand for roughly half the microwaving time. Mar 6, 2002