Posted on: 21/11/25

The leaves are on the ground, the big coats are out, and it’s dark by 4.30 pm.

For warehouses and large storage spaces managing temperature-sensitive products and samples – from pharmaceuticals and blood products to research samples and vaccines – there’s a unique set of challenges to be faced when the colder months roll in.

As heating systems start working overtime to maintain controlled indoor conditions, the onset of winter is a critical time to re-validate your temperature mapping and ensure your storage areas remain compliant.

Even small variations in temperature distribution can compromise product integrity, trigger compliance breaches or lead to catastrophically expensive product loss.

How winter conditions affect temperature-controlled environments

Cold weather can be deceptively disruptive. When external temperatures fall, internal conditions often become uneven, particularly in large or high-ceilinged warehouse spaces.

Doors opening to loading bays or unheated corridors can create draughts and cold zones, while heaters or unevenly insulated areas may cause localised warm spots.

These inconsistencies can make it harder to keep temperatures stable across an entire space, especially in warehouses that combine ambient, chilled and refrigerated zones.

Your refrigeration units and environmental control systems might need to work differently, sometimes cycling less frequently or over-correcting for cold air ingress.

The result can be temperature stratification – where upper levels remain warm while lower levels dip below the required threshold – or the opposite, with heating systems introducing unexpected warmth near sensitive products and samples.

Why winter temperature mapping is essential

A temperature mapping study helps you identify exactly how your warehouse or storage environment performs during real-world seasonal conditions.

During winter, mapping allows you to:

• Detect cold spots or over-cooling caused by poor insulation, door openings or heating and ventilation (HVAC) imbalances.
• Verify that heaters and defrost cycles are not creating unwanted warm zones.
• Ensure compliance with MHRA, GDP and other regulatory standards that require mapping under representative seasonal extremes.
• Re-validate previous mapping data to confirm any changes made since the last study – such as equipment moves, layout adjustments or building works – have not altered your thermal profile.

Most importantly, winter mapping provides reassurance that your compliance evidence remains current. Regulators expect to see seasonal mapping every one to three years, or whenever significant environmental changes occur.

Conducting a winter validation helps you demonstrate due diligence and inspection readiness at any time of year.

How often should warehouses be temperature-mapped?

The recommended interval depends on your sector and the criticality of the products and samples being stored. As a guide:

• Pharmaceutical and healthcare environments – typically re-mapped every 12 to 24 months or following any significant layout or system change.
• Research, life sciences and cold-chain storage – generally annually to ensure compliance across all temperature-controlled spaces.
• General warehousing or bulk ambient storage – at least every three years, with additional mapping if major modifications occur.

Seasonal mapping – once in summer and once in winter – provides the most complete thermal profile, helping you demonstrate compliance under both hot and cold extremes.

When to schedule your winter mapping

The ideal time for winter mapping is mid-winter, typically December through February, when external temperatures are at their lowest. This ensures your mapping data captures the worst-case seasonal conditions and reflects how your facility performs under natural cold-weather stress.

To avoid disruption, schedule early. Installations and collections of mapping sensors take place during normal office hours, but the sensors remain running 24 hours a day, seven days a week.

Mapping durations vary. While 24 and 48-hour studies are the most common, warehouse mapping and other large areas can run for up to 7 days. We can also carry out mapping in both full and empty states for fridges and freezers, which is typically required for new equipment validation and revalidation of critical equipment.

Results are compiled into a full UKAS-accredited temperature mapping report suitable for audit submission.

Why re-validation protects more than compliance

Beyond regulatory requirements, here’s how winter re-validation supports your wider operational resilience:

• Avoid costly spoilage - by identifying areas where products could fall out of specification.
• Improve energy efficiency – balanced temperatures reduce over-cycling of refrigeration or heating systems.
• Protect staff and assets – by understanding airflow, door-open patterns and how they influence working zones.
• Maintain customer trust – consistent storage conditions support product and sample quality and supply chain confidence.

The insight gained from mapping can also help you optimise equipment placement, insulation and airflow management, saving energy and improving consistency all year round.

Make compliance easier with Contronics

Contronics’ temperature mapping service is trusted by the NHS, pharmaceutical manufacturers and laboratories across the UK. As a UKAS accredited company, we deliver mapping to ISO 17025 standards to support compliance across a wide range of regulated environments.

We install and collect all mapping data using calibrated sensors, analyse the results and deliver a comprehensive report with clear recommendations so you can demonstrate compliance with confidence.

To make long-term compliance planning simpler, Contronics offers a three-year, discounted temperature mapping package. This provides continuity, cost savings and removes the need to re-order each year.

Prepare your site for the season ahead

If your last temperature mapping was completed before last winter, or if your site has undergone any layout, equipment or HVAC changes, now is the time to schedule a new study.

Don’t wait until temperature alarms start sounding or an audit is due. Get proactive, protect your products and simplify compliance with Contronics.

Book your winter temperature mapping study or request a quote today.

Our specialist team will help plan the right schedule for your site, keeping your operations running smoothly – whatever the weather brings.