The inside of a fridge is not at one temperature, and which zone is unstable depends on the type of unit. According to the CDC vaccine storage toolkit (2024), in a household-type fridge the area under the cooling vent, the drawers and the door shelves are unstable and do not count as product locations; the freezer compartment is not recommended, and mini-bar type units are not used at all.
- Boxes stay in their original packaging with lids closed, each type in its own container.
- Leave 5-7 cm (2-3 inches) from the walls, ceiling, floor and door; leave air between rows.
- Put the earliest expiry dates at the front.
- Place the sensor tip in the middle of the products; product temperature is shown by a calibrated logger with a buffered probe, not by an ordinary air thermometer.
- Keep food and drink out; water bottles steady the temperature.
A newly installed or repaired unit takes 2-7 days to stabilise; before medicines go in, the minimum and maximum are recorded each working day for that period.