How heat is becoming the new supply chain disruptor and how can cold chain leaders prepare?
While the UK and most of Europe continue to navigate one of the hottest summer periods on record, a clear operational challenge has impacted the shelf-edge. Heat is now the latest headwind for the industry whether it’s down to struggling in-store refrigeration or maintaining cold-chain integrity through the distribution network. Higher ambient temperatures are putting more consistent strain on refrigeration units than ever before.
When Marks & Spencer told shareholders it was investing in refrigeration capable of operating in 45°C conditions, it marked an important shift in how the industry thinks about climate risk. This was not a sustainability announcement but an operational one. Following a Europe-wide June heatwave that pushed UK temperatures to a record 37.7°C, refrigeration units in some stores and food halls failed, forcing the retailer to review its cooling estate and invest in more resilient equipment. Competitors faced similar challenges, with Sainsbury's also accelerating refrigeration upgrades across its store network. Across multiple major retailers, open-fronted chiller units also had to have blinds drawn to reduce failure risk.
The significance extends beyond a single heatwave. Retail cold chains have traditionally been designed around historical weather patterns. Climate change is now rendering those assumptions obsolete.
The latest IGD climate risk assessment highlights the scale of divergence between climate pathways by 2050. Under a Net Zero scenario, the assessed impact on the UK food system is broadly neutral. Under a Delayed Transition scenario, the impact rises to £1.4bn. Under a Business as Usual pathway, costs increase to £2.6bn, equivalent to almost 15% of annual food commodity costs across the commodities analysed. Climate risk is no longer primarily an agricultural issue. It is increasingly an infrastructure and asset performance issue.
Store refrigeration is the visible manifestation of the problem, but transport is arguably more vulnerable.
A refrigerated trailer operating at 15°C ambient temperature and one operating at 30°C ambient temperature are fundamentally different assets. Compressor duty cycles increase, refrigeration units consume more energy, equipment experiences greater mechanical stress and temperature recovery times lengthen following door openings.
The industry is already responding. Manufacturers such as Carrier Transicold are now marketing transport refrigeration systems specifically designed to operate in ambient temperatures of up to 50°C, a capability previously associated with Middle Eastern or Australian markets rather than Europe.
For food retailers and manufacturers, this matters for three reasons.
First, operating costs will rise. More cooling capacity means greater energy consumption across both stores and transport fleets. For operators transitioning to battery electric refrigerated transport, higher ambient temperatures will also reduce available range as more power is diverted towards cooling rather than propulsion.
Second, asset utilisation will decline unless networks adapt. Longer pre-cooling periods, reduced trailer productivity during extreme heat events and increasing maintenance requirements will create hidden capacity constraints. A fleet sized for today's climate may not be sufficient for tomorrow's.
Third, food safety risks become harder to manage. Temperature excursions often occur during loading, unloading and store replenishment windows. As external temperatures rise, the margin for error narrows. Products spend less time outside controlled environments before quality degradation begins.
The challenge is amplified by sourcing patterns. IGD's assessment identifies imported horticulture as the category most exposed to climate risk, with citrus, bananas and tomatoes particularly vulnerable. Many of these products already move through complex refrigerated supply chains over long distances. Climate stress at origin, combined with increasing stress within transport and retail infrastructure, creates a compounded risk profile.
What makes this issue strategically important is that cold chain resilience has historically been treated as an operational concern rather than a board-level risk. M&S's decision suggests that perception is changing.
Today's discussion is often framed around reducing emissions from refrigeration systems. That remains important. However, adaptation deserves equal attention. The question is no longer whether higher temperatures will affect cold chain operations. They already are.
The more useful question is whether existing assets, networks and operating models were designed for the climate conditions now emerging.
Key actions for supply chains
Stress test assets against future climate conditions, not historic averages. Refrigeration specifications designed for 30°C peak temperatures may be insufficient for future operating environments.
Model cold chain performance under extreme heat scenarios. Understand the impact on fleet productivity, energy consumption, maintenance requirements and service levels.
Invest in real-time temperature visibility. Temperature excursions increasingly need to be predicted and prevented rather than identified retrospectively. IoT-enabled monitoring is becoming a resilience tool, not simply a compliance tool.
Review store formats and refrigeration design. The M&S example highlights that refrigeration resilience is becoming part of core retail infrastructure planning, not a facilities management issue.
For much of the past decade, climate discussions in food supply chains have focused on carbon. The next decade will increasingly focus on heat. The winners will be those who recognise that refrigeration is no longer a utility. It is becoming a strategic capability.
Want to read more insight on coldchains? Read our full report on Energy efficient cold chains.