Thus, it is recommended that refrigerators be maintained at 40oF (4.4°C) or below.
However, no recent extensive studies have been reported that assess actual temperatures at which cold foods are stored over time within the home. The objective of this project was to evaluate
the temperatures of refrigerators in 200 homes in the United States.
Loggers were used to record temperatures each minute in several locations in each refrigerator. In some homes, a thermocouple was also placed in a commercially sealed hot dog and in a cup of
yogurt.
Data were analyzed using Excel and SPSS-PC. Mean temperatures were 35.5, 38.0 and 41.3°F (1.9, 3.3 and 5.2°C) for the top shelf, bottom shelf and door, respectively, with 9, 25 and 61%
of these areas having average temperatures above 40°F (4.4°C). Over 66% of refrigerator door temperatures were above 40°F (4.4°C) for more than eight hours per day. The
temperature of the foods fluctuated less than the temperature of the surrounding air.
Temperatures rose above the danger zone (above 40°F or 4.4°C) for more than 2 hours a day for 33%, 45%, and 80% (top shelf, middle shelf, door, respectively) of refrigerators.
Consumers need to check the temperature regularly and should be advised to store temperature-sensitive foods on the top shelf of the refrigerator when appropriate.

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