What counts as an excursion
An excursion is any time product is exposed to temperatures outside the range on its label or package insert — too warm or too cold. Freezing of a refrigerated vaccine counts just as much as warming; many vaccines are damaged by freezing, and the damage is not visible.
Brief spikes in air temperature caused by door openings, seen on an unbuffered sensor, may not mean the product left its range. That is one reason buffered probes placed among the stock are recommended.
First steps: protect, don't discard
- Tell the person responsible for cold chain at once — the vaccine coordinator, pharmacist in charge or cold chain handler.
- Get the product back into correct storage: fix an open door, or move stock to a working backup unit.
- Label affected stock clearly — the CDC suggests 'DO NOT USE — TEMPERATURE EXCURSION' — and keep it separate from other stock.
- Do not throw it away and do not use it until a decision is made.
- Do not keep adjusting the thermostat in a panic; follow your procedure and verify with a second device if the reading looks doubtful.
Record what happened
| Item | Why it is needed |
|---|---|
| Date, time and duration out of range | Manufacturers assess exposure by magnitude and time |
| Minimum and maximum temperatures reached | Shows whether the risk was heat, cold or both |
| Room temperature, if known | Helps explain the cause |
| Products, lot numbers and quantities affected | Needed for any usability decision and stock records |
| Logger data download | Objective evidence of the event |
| Previous excursions for the same stock | Exposure can be cumulative |
| Likely cause and actions taken | Supports the investigation and prevention |
Get a decision from the right authority
For vaccines supplied through India's Universal Immunization Programme, report through programme channels — your cold chain handler, medical officer or district immunization officer — and follow their instructions. Programme staff are trained in procedures such as the shake test for suspected freezing of certain vaccines; those are done by trained staff under programme rules.
For privately purchased vaccines and medicines, contact the manufacturer or distributor with your records, and follow your State Drugs Control authority's expectations. The CDC's guidance is the same in principle: vaccines exposed to out-of-range temperatures should not be used unless the manufacturer or public health authority confirms they remain safe and effective.
Find and fix the cause
- Door left open or not sealing — check gaskets, hinges and whether the cabinet is level.
- Power failure or tripped socket — check backup power and plug security.
- Thermostat changed or controller fault — compare against a calibrated reference.
- Condenser blocked by dust or the room much hotter than usual.
- Overloading or warm stock added in bulk.
- Probe moved or logger fault — check placement and calibration.
Close the loop
Record the final outcome: whether the stock was used, shortened in expiry, returned or discarded, who decided and on what basis. Note what will change — a door alarm, a new backup arrangement, a cleaning schedule — so the same excursion doesn't happen again.
Keep these records with your temperature logs. They are part of the evidence that your storage system works, and they often reveal patterns — the same fridge every summer, the same long weekend — that a single event hides.
Prepare before it happens
- A one-page excursion procedure posted beside each fridge, with phone numbers.
- A backup cabinet or arrangement, and insulated boxes with conditioned coolants ready.
- Loggers with alarms that reach someone out of hours.
- A pre-printed excursion report form.
Frequently asked questions
- Can I decide myself that vaccines are fine if the excursion was short?
- No. Usability depends on the product, the temperature reached, the duration and any previous exposure. Send the details to the manufacturer, your immunization programme or regulator, and wait for their decision.
- Should I throw out stock immediately after an excursion?
- No. Quarantine it in correct storage, labelled 'do not use', until you have a decision. Discarding early can waste usable stock, and you lose the evidence needed for the report.
