Take immediate remedial action
Check and rectify obvious causes, e.g. air conditioning switched off, door left open or blinds left open during a heatwave.
Fridges and freezers
Check and rectify obvious causes e.g. the fridge door has been left open or a power switch has been turned off. Keep the fridge/freezer door closed as much as possible. Check that temperature sensors are in the right place and are working correctly.
The fridge should be returned to use only once it has been confirmed to be functioning correctly:
- confirm the fridge has returned to 2°C to 8°C and, once documented, reset the min/max fridge reading and alarm (if you have them)
- where no obvious rectifiable cause can be identified, take the fridge out of use until an investigation into the cause of the excursion has been concluded and apply a suitable sign/label to show that the fridge is out of use
Quarantine affected medicines
Secure and quarantine the affected stock, attaching a “DO NOT USE” label.
If the entire contents of a storage area (e.g. a fridge or freezer) is quarantined attach the label to its door.
Transfer to a more suitable storage area if possible.
Some medicines (e.g. creams, ointments, suppositories) may be best transferred to a fridge if there is no cool place to store them. Check with a pharmacist whether this would be appropriate.
Any medicines that have been exposed to temperatures outside of 2°C to 8°C should be returned to refrigerated storage.
If the fridge has not gone back to its correct temperature range, transfer the medicines to another fridge if possible.
Keep the stock in a freezer.
If your only freezer is broken, leave the stock inside it but keep the door shut to keep it as cold as possible.
Gather excursion information
Establish the circumstances
- find out what happened
- determine how it happened
For example, if this relates to a fridge, was the fridge switched off or did the fridge malfunction? Were the medicines left out of the fridge?
Information about the temperature
Collect the following information:
- what happened overall
- how warm the medicines became (maximum temperature reached)
- how cold the medicines became (minimum temperature reached)
- the total time the storage area was outside its recommended storage temperature range
If you are not sure about any of these details, use a “worst case” scenario.
Min / max temperature recorder
Assume that the temperature excursion started just after the recorder was last reset unless you have information to the contrary.
This is because a min / max temperature recorder (or thermometer) records the lowest and highest temperatures the storage area has experienced since the recorder was last reset. Consequently, you do not know whether that low / high temperature happened just after the recorder was reset, or just before you looked at it.
Continuous data logger
Where a continuous data logger is in use, download and examine the data.
Continuous data loggers can provide a more detailed picture of temperatures within the storage area than min / max recorders and are more helpful in aiding decision-making in the event on a temperature excursion.
Assess the significance
Most medicines may be stored at temperature up to 25°C, some allow up to 30°C and some medicines have no storage conditions specified by the manufacturer.
A single, isolated excursion of less than 5°C above the specified maximum storage temperature for less than 7 days is unlikely to have an adverse effect on the medicines.
However, if you have a Wholesaler Dealer’s Licence or if there are other additional regulatory requirements, you should ensure that all of these requirements are met.
Some electronic systems can calculate the Mean Kinetic Temperature (MKT) which “smooths out” peaks and troughs and gives an overall temperature reading for the period in question. For example, the temperature in an ambient area may exceed 25°C for a few hours during one afternoon, but over the course of the whole day the MKT may only be 23°C. In this case the excursion can be disregarded.
Studies from the U.S National Institute of Standards and Technology have shown that vaccine vials can maintain temperature below +8°C for a minimum of 20 minutes in situations where there is a continuous influx of ambient air into the fridge or loss of power. Therefore, if the excursion above +8°C is for less than 20 minutes and the medicines are stored in their original packaging, it will be unlikely that the medicine itself will have warmed above 8°C. The study related to vaccines, however it is reasonable to extrapolate the findings to other refrigerated medicines.
Excursions below 2°C are always potentially significant and should be fully explored.
All temperature excursions are potentially significant. Seek expert advice if necessary.
Collect product details
The following product information should be gathered:
- medicine name (generic)
- brand name
- pharmaceutical form (tablet / capsule / injection)
- batch number and expiry date (may sometimes be required)
- if the medicine has been exposed to a previous temperature excursion
Find stability information
Find stability information for medicines, vaccines or parenteral nutrition from reputable sources.
Manufacturer’s product information
The Summary of Product Characteristics (SmPC) is the manufacturer’s information sheet for healthcare professionals. It includes storage instructions, sometimes including information on what to do if the medicine has been exposed to a temperature excursion.
The current SmPCs can be found online:
- Electronic Medicines Compendium (eMC)
- Medicines and Healthcare Products Regulatory Agency (MHRA) website
- manufacturer’s website
Ensure that you use the current SmPC for the correct brand because storage information sometimes differs between brands. Use the Product Licence / Marketing Authorisation number printed on the packaging to check if you are not sure.
The SPS website
Manufacturer’s medical information department
The product’s manufacturer may have additional stability data beyond that in the SmPC. When you contact the manufacturer, make it clear that you would like this additional stability data to enable you to make your own risk assessment regarding the suitability of the medicine for use.
Use the following resources to find contact numbers for manufacturers:
Information on responding to temperature excursions involving vaccines can be found in the UK Health Security Agency’s Vaccine incident guidance: responding to vaccine errors.
All incidents occurring in NHS provided immunisation programmes should be reported to the local NHS England and Improvement (NHSEI) Screening and Immunisation or Public Health team. Serious vaccine incidents should be dealt with in line with the NHS England Serious Incidents Framework.
The SmPC is now often a good source of information on temperature excursions, so you should check this first.
The British Pharmaceutical Nutrition Group has information on stability and temperature excursion information for parenteral nutrition.
If you are unable to find all the information you need to make a decision, or need help interpreting the information, contact:
- SPS Medicines Advice service for primary healthcare professionals in England
- your local medicines information or advice service
Decide whether the medicine has been affected
Once you have gathered all the information it should be possible to make a judgement about whether the product has been affected by the exposure to the low or high temperature. If the product has not been affected it may be used without any further action except taking steps to prevent recurrence and documenting as below.
Confirm if affected medicines can be used
If you have concluded that the medicines have been affected, they may still be suitable for use with risk mitigation measures.
Consider the following when undertaking a local risk assessment to determine whether the affected medicines can be used:
- medicines which are nearing the end of their shelf-life may be more likely to be unsuitable for use after a temperature excursion
- the effect on the patient of any potential reduction in efficacy. Will additional monitoring be necessary? What are the short- or long-term consequences?
- the potential for toxicity, if any
- if no further supply is available, the effect on the patient of not receiving the medication
Your conclusion is likely to be one of the following:
- the medicine is suitable for use but its remaining shelf-life needs to be shortened
- the medicine is suitable for use but the patient will require additional monitoring
- the medicine is not suitable for use and should be discarded
Consider the need for further advice
Consider seeking further advice if you do not have enough information to make the decision yourself. This could be someone with expert knowledge of medicines stability, a clinician with knowledge of the use of the medicines, your manager, or a combination of these individuals.
Actions will be determined by whether the medicine can be used, or if it needs to be destroyed.
Use the medicine
If the medicine can be used:
- return the medicine to the correct storage area if it has been removed
- consider applying a sticker to alert staff to the fact that the medicine has previously experienced a temperature excursion
- ideally, the sticker should give details of the temperature excursion so that these can be taken into account if a further excursion should happen
- shorten the shelf-life as necessary in line with your local policies; ensuring the original shelf-life has been obscured but the batch number is still visible
Destroy the medicine
If the medicine must be destroyed:
- make an appropriate entry in the pharmacy stock control system
- remove the medicine from the medicines storage area and dispose of it as appropriate
- order further supplies if necessary
Your investigation of the temperature excursion should have identified the reason it happened.
However, you should also consider the root causes such as lack of staff training or need for equipment to be serviced. In all cases, be sure you understand why the increase in temperature happened so that recurrence can be prevented.
Following our good practice advice on fridge use will help you prevent recurrence of excursions.
Record the outcome
All excursion incidents should be fully documented locally, no matter how minor.
Recording all incidents means that you will be able to see if there is a pattern, which could reveal a developing problem.
As a minimum, record:
- your identity
- the time and extent of the temperature excursion
- details of the medicines and batch numbers affected by the temperature excursion
- details of any advice taken and whom this was sought from
- actions taken to prevent a future reoccurrence of the excursion
- record the event according to your adverse incident recording procedure
A checklist to aid information gathering in the event of a temperature excursion of COVID-19 vaccines.
- Clarification of requirement to report vaccine related incidents.
- Added additional detail to 'assess the significance' - fridge section. Added 'Useful resources' section. Several minor clarifications throughout the page