Quick reference guide
Our quick reference guide provides guidance on how to set up and monitor your fridge. Key points from the guide are also summarised on this page together with signposting to other resources.
In-built fridge thermometers normally measure the air temperature in the fridge.
We recommend that in addition to monitoring the air temperature of the fridge, a temperature probe should be placed into a “mock up” product close to the stored vaccines. This is known as a “load probe”. This probe will more accurately represent the effect of temperature fluctuations on the temperature of the vaccine itself.
The temperature probe in the air may register transient out of limit temperatures during normal opening and closing of the door, so the load probe thermometer can be used to give assurance that the vaccine itself has remained within range at all times.
The load probe can also be useful in establishing the lag time between the air temperature and load temperature going out of range. This information can be used to set alarm delays and alarm thresholds.
The load probe can be useful in investigating the effects of a fridge failure. If the load probe is attached to a datalogger rather than max/min thermometer this will give additional useful information about the length of the temperature excursion.
Use of an alarm may be helpful in monitoring temperature and where deviations occur. To be effective alarms must:
- Be set correctly with the necessary parameters
- Sound correctly to inform staff when a temperature monitoring issue occurs
Fridges must be maintained if they are to continue to be effective. This should include:
- A routine service and maintenance programme
- Annual calibration of temperature sensors
The Green Book (Chapter 3) provides essential detailed guidance for maintaining the vaccine cold chain.