Temperature Mapping in a Pharmaceutical Warehouse

What temperature mapping is

Temperature mapping assesses how temperature behaves across a storage space — identifying any warmer or cooler spots so that conditions can be trusted everywhere product is stored, not only at a single monitoring point. It answers the question: "is the whole zone actually within range?"

Why mapping is not optional

Warehouses are not perfectly uniform — areas near doors, walls or airflow can differ. Without mapping, product in a hot or cold spot could sit outside range unnoticed. For pharmaceuticals, that is a real risk to potency and a gap in compliance. Mapping and ongoing monitoring close that gap.

Mapping and continuous monitoring together

Mapping establishes that a zone holds its conditions; continuous monitoring with alarms then keeps watch over time, catching drift before product is affected. Together they turn "we set it to the right temperature" into "we can show the whole zone stayed in range."

How SFIMS maintains temperature integrity

SFIMS operates its DOH & MOH approved zones with continuous temperature logging and escalating alarms, producing the documented record that underpins temperature integrity and supports audits.

How a mapping study is actually run

A study is a controlled experiment on the space, not a walk round with a thermometer:

• Sensors placed to find extremes — top and bottom of racking, beside doors, near cooling outlets, in corners, against external walls — rather than in convenient positions.
• Enough of them. A large room needs a grid, not a handful.
• Run for a meaningful period, long enough to capture the daily cycle and normal operation including door openings.
• In worst-case conditions. A summer study describes the facility you actually operate; a winter one does not.
• Loaded and empty. Stock changes airflow, so a full room behaves differently from an empty one.
• Calibrated sensors, with the certificates retained as part of the study.

Reading the results and acting on them

The output is not a pass mark. It is a map, and its value is in what changes afterwards.

Hot and cold spots are located and either corrected — airflow, racking layout, additional cooling — or designated as areas where product is not stored.

Permanent sensor positions are then chosen from the study, placed at the extremes it identified. This is the step most often skipped: monitoring a comfortable spot afterwards defeats the purpose of having mapped the room at all.

Alarm thresholds are set with enough margin to allow a response before product leaves range, rather than at the moment it already has.

The report is retained as evidence, because an inspector will ask not only whether mapping was done but what it found and what happened next.

When mapping has to be repeated

A study describes the room as it was on the day. It stops being valid when the room changes:

• Racking added, removed or reconfigured.
• Refrigeration plant replaced or significantly serviced.
• Doors, insulation or the building fabric altered.
• A change in how the space is loaded, such as much denser storage.
• New temperature bands introduced.
• Persistent alarms suggesting behaviour the study did not predict.

Periodic re-mapping is also expected regardless of change, because equipment performance drifts. A study carried out once at commissioning and never repeated is among the more common findings in an inspection.