Understand sensor location, recording intervals and temperature excursions in transport records, and organize evidence for the responsible product owner's review.
In This Guide
What It Means
A temperature log is a time-stamped series of readings at a sensor location and configured interval. It may describe supply air, return air, compartment air or a product measurement. Gaps, location, calibration and method limit what can be inferred; it does not show every product's exposure.
An excursion is a recorded condition outside the shipment's written range. Duration, magnitude, measurement context and product-specific evidence need review by the responsible quality team. Mean Kinetic Temperature is not a universal food or produce disposition method.
Why It Matters
- Temperature logs are the primary evidence in any product quality dispute or insurance claim related to a cold chain shipment
- Logs may support an investigation alongside pickup condition, handling and other evidence; they do not independently assign liability
- Pharmaceutical products often require formal excursion analysis before the product can be released or destroyed — a log is not optional
- Cannabis QA teams use temperature logs to support or contest distributor quality holds
- Reading a log helps organize evidence; product-risk and disposition decisions belong to responsible specialists
How It Works
What a Temperature Log Shows
- Timestamp of each recorded data point (typically every 5, 10, or 30 minutes)
- Interior trailer temperature at each recording interval
- Any alarm triggers (typically at pre-set upper and lower limits)
- Logger start time (should match or precede loading) and stop time (should match or follow delivery)
- Summary statistics: minimum temperature, maximum temperature, average temperature, and sometimes Mean Kinetic Temperature
Identifying an Excursion
Compare recorded temperatures against the specified acceptable range for the product. Any data point outside the range is a potential excursion. Focus on: the magnitude of the deviation (how far outside range), the duration (how many consecutive readings), and the timing (early in transit when product is still at set point vs. late when product has been conditioned).
Assessing Severity
- Preserve original readings, units, location and recording interval
- Document door openings, equipment alarms and gaps without assuming their cause
- Compare like measurement types against the written instructions
- Notify the product owner or quality team using the current exception procedure
- Do not use this guide to approve, release, reject or dispose of product
Common Challenges
- Logger not started until after loading, creating a gap in the pre-cooling verification record
- Logger placed near the refrigeration unit rather than in the load, recording unit output rather than product temperature
- Missing logs — carrier claims tracking occurred but no logger data is provided at delivery
- Misinterpreting door-opening spikes as product-impacting excursions without accounting for duration and recovery
- Not knowing the product's acceptable range and therefore being unable to evaluate the log at all
Best Practices
- Specify logger placement in your transport SOP — mid-trailer, mid-height, away from the refrigeration unit and doors
- Start the logger before loading and confirm start time is recorded on the bill of lading
- Retrieve the logger at delivery — do not rely on the carrier to deliver the data
- Know your product's acceptable temperature range and alarm thresholds before reviewing any log
- For pharmaceutical and cannabis products, have a written excursion evaluation procedure before you ever receive a log with a finding
- Archive all temperature logs with the associated transport record and POD
When to Use This Service
- Any temperature-sensitive shipment where product integrity at delivery must be documented
- Pharmaceutical and cannabis shipments where regulatory compliance records require temperature evidence
- Fresh produce shipments where shelf-life at delivery is the basis of buyer acceptance
- Any shipment where insurance coverage for temperature damage depends on documented excursion evidence
OTR coordinates monitoring and record requests for the shipment, subject to assigned carrier and equipment capability. The shipper or product owner supplies logger, placement, threshold and exception requirements; records are not included automatically.
Read temperature-controlled freight guides, the temperature-controlled quote checklist and our food and beverage freight service.
Planning references only—not legal advice, food-safety certification, product-disposition or carrier approval, substitutes for shipper SOPs or product-owner instructions, or guarantees of shelf life or product condition. Confirm written instructions with the responsible parties.
Numerical commodity examples are general references, not universal transport temperatures or shipment instructions. Follow the product owner’s, shipper’s and receiver’s current requirements.
Official food-transport references
CFIA and FDA explain applicable legal requirements and role-based responsibilities, including scope and exceptions. USDA’s historical handbook is technical guidance, not current law. OTR’s checklists and tools are planning recommendations, not compliance certification. Confirm current applicability with the responsible shipper, importer and appointed customs broker.
Frequently Asked Questions
What types of temperature loggers are commonly used in freight?
The most common types are single-use USB loggers (downloaded at delivery via computer), reusable Bluetooth loggers (downloaded via smartphone app), and cellular loggers (transmit data in real time to a web portal). For most commercial freight, a reusable logger with downloadable data is adequate. Pharmaceutical and cannabis moves increasingly use real-time cellular loggers for immediate excursion notification.
What is Mean Kinetic Temperature and when is it relevant?
Mean Kinetic Temperature (MKT) is a single calculated temperature that accounts for the non-linear effect of temperature on chemical degradation. It is primarily used in pharmaceutical cold chain management to assess whether cumulative temperature exposure during transit exceeded acceptable limits. Your QA or regulatory affairs team will determine whether MKT analysis is required for your specific products.
What should I do if the carrier cannot provide a temperature log at delivery?
Document the missing log on the proof of delivery. Notify your QA team. If the shipment is pharmaceutical or cannabis, the absence of a log may require a hold pending investigation. Contact your freight broker immediately — the carrier's failure to provide documentation is a significant service failure that must be addressed in writing.
Can a single high-temperature reading at delivery invalidate an entire shipment?
A single reading cannot establish product condition or disposition. Preserve its context, measurement type, units and timing and escalate under the product owner's procedure. Do not assume it is harmless or proof of damage.
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