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This page describes products and general use; it is not medical advice.
A medical refrigerator for vaccines must hold 2 °C to 8 °C (36 °F to 46 °F) at all times, according to the CDC’s July 2026 Vaccine Storage and Handling Toolkit. The thermostat dial cannot confirm that: only a measuring device can, so a new unit needs a stabilisation period and a recorded log before it holds stock. Who uses it: clinic and pharmacy staff, immunization coordinators and the buyers who equip them. For the unit itself (types, how it differs from a household fridge), see the medical refrigerator guide; this page is the temperature reference.
What it is
A medical refrigerator used for vaccine storage is a refrigerated unit whose temperature is measured and logged, not assumed from the dial. This page covers the temperature rules; the unit itself is covered in the guide linked above.
Specifications
Required temperature ranges
For vaccine storage, the CDC toolkit (July 2026 edition) states that units must maintain these ranges at all times:
| Storage unit | Required range |
|---|---|
| Refrigerator | 2 °C to 8 °C (36 °F to 46 °F) |
| Freezer | -50 °C to -15 °C (-58 °F to +5 °F) |
| Ultra-cold freezer | -90 °C to -60 °C (-130 °F to -76 °F) |
These are CDC vaccine rules, not a universal rule for every pharmacy or laboratory product. The manufacturer’s label governs each product, and some products carry different ranges (the toolkit gives a frozen vaccine labelled -40 °C to -15 °C as an example).
How it is built
The control and measurement parts matter more than the cabinet here: a thermostat, which only sets the target, and a separate measuring device, which confirms the result.
Thermostat setting
The toolkit advises setting the thermostat at the factory-set or midpoint temperature, for example 5 °C (41 °F) for a refrigerator, to reduce the risk of excursions. It also notes that thermostats generally show levels of coldness rather than temperatures: the only way to know a unit’s temperature is to measure and monitor it with a temperature monitoring device.
Commissioning a new or repaired unit
The CDC states that a newly installed or repaired refrigerator may take 2 to 7 days to stabilise (2 to 3 days for a freezer). Before storing vaccine, check and record the minimum and maximum temperatures each workday for 2 to 7 days. If temperatures cannot be recorded digitally, record them at least twice each workday. After 2 consecutive days within the recommended range the unit is considered stable and ready for use.
Types
Measuring devices
The CDC recommends digital data loggers (DDLs) for routine storage, transport and temporary clinics. A simple min/max thermometer shows only the coldest and warmest temperatures reached; a DDL records all temperatures at preset intervals.
| Item | What the CDC toolkit says |
|---|---|
| Thermostat dial | Shows levels of coldness, not temperature. |
| Min/max thermometer | Shows only the coldest and warmest temperatures reached. |
| Digital data logger | Records every temperature at preset intervals. |
| Buffered probe | Gives the most accurate measurement of vaccine temperature; standard thermometers typically measure air temperature. Place it in the centre of the unit with vaccines surrounding it. |
| Calibration | Test every 2 to 3 years, or per the manufacturer’s schedule; each device should have a current, valid Certificate of Calibration Testing, kept accessible. |
For monitoring systems and alarms, see the temperature monitoring system guide and the dictionary entry on a temperature monitoring alarm.
How to choose
The CDC states these criteria for the measuring device: a digital data logger is recommended for routine storage, a buffered probe gives the most accurate vaccine temperature, and each device should have a current Certificate of Calibration Testing. The measuring-device table above lists the details.
Safe use
Temperature log
The CDC toolkit lists these fields for the temperature log:
- Minimum and maximum temperature
- Date and time
- Name of the person who checked and recorded
- Any action taken if a temperature excursion occurred
At the start of each workday, check and record the minimum and maximum. If the device has no min/max function, record the current temperature at least twice per workday, at the start and end. If a reading is missed, leave a blank entry in the log rather than filling it in later. The toolkit says to keep logs for 3 years to track trends and recurring issues.
A reading outside the range
Record any action taken in the log, and see temperature excursion: what it means and how to respond. The wider CDC process is covered in the CDC Vaccine Storage and Handling Toolkit guide.
Common mistakes
- Trusting the dial: it shows coldness, not temperature.
- Loading stock before the unit has had 2 consecutive in-range days.
- Reading an air-temperature thermometer when stock temperature is what matters (the CDC points to a buffered probe).
- Using a device without a current Certificate of Calibration Testing.
- Back-filling a missed reading instead of leaving it blank.
FAQ
What is the correct temperature for a medical refrigerator?
For vaccines, the CDC requires 2 °C to 8 °C (36 °F to 46 °F) at all times, with the thermostat set near the 5 °C (41 °F) midpoint. Other products follow their own labels.
How often should the temperature be recorded?
The CDC toolkit says to check and record the minimum and maximum at the start of each workday; with no min/max function, at least twice per workday.
How long should temperature logs be kept?
The toolkit says 3 years.
How long does a new refrigerator take to be ready?
It may take 2 to 7 days to stabilise; it is ready after 2 consecutive days of recorded temperatures within range.
What does a pharmacy refrigerator temperature log include?
Per the CDC toolkit: minimum and maximum temperature, date, time, the name of the person who checked and recorded, and any action taken if a temperature excursion occurred.
Sources
- CDC, Vaccine Storage and Handling Toolkit, July 2026 edition (PDF), checked 2026-11-01. Landing page: CDC storage and handling.
