Britain’s increasingly scorching summers are exposing weaknesses in the systems retailers rely on to keep food safe; from the refrigeration units in supermarkets to the trucks and warehouses that move chilled and frozen products around the country.
This year’s heat has already provided a warning. The Met Office recorded temperatures of 35C or higher in May, June and July for the first time in the UK’s weather record, while eight days have so far exceeded 34C, surpassing the previous record held by 1976 and 2020.
The impact has been visible to shoppers. During the latest heatwave, supermarket fridges and freezers failed at stores across the country, leaving some chilled and frozen food sections empty. Problems have been reported at many of the leading retailers including Tesco, M&S and Sainsbury’s, while industry figures warned that older refrigeration systems were particularly vulnerable to extreme temperatures.
But ‘consumer-facing’ refrigeration is only one part of the problem, as behind the supermarket shelves is the cold chain, the network of refrigerated storage, vehicles and distribution centres that keeps food at the right temperature as it travels from producer to retailer.
At this point in the supply chain, failures such as a trailer running too warm, a pallet sitting on a loading bay or a delivery taking too long to reach refrigeration, can put the product at risk of being spoilt.
For Wiliot, a technology company that describes itself as a “physical AI platform”, vice president Amir Khoshniyati, the challenge is that much of the industry still relies on intermittent checks rather than continuous visibility.
Its technology uses small, battery-free Bluetooth Low Energy tags, which can be attached to physical products and powered by ambient radio waves. The tags can transmit information including location, temperature and humidity, while also detecting exposure to light, which could indicate that a package has been opened.
The company’s argument is that this can close a gap in the cold chain that traditional monitoring may miss.
“If they’re a trailer that’s supposed to be holding something at, let’s say, around 72 degrees, and now it’s starting to go through the same routes that are 10, 15 degrees warmer, we’ve all been in rooms with a lot of glass,” said Khoshniyati. “If there’s a 10 degree temperature change on a very sunny day, you’re going to feel warmer in that room. These trailers operate the same way.”
The point, he said, is that refrigeration infrastructure may be capable of maintaining a set temperature under normal conditions, but increasingly hot weather can put additional pressure on the system.
The problem is not necessarily confined to the journey itself. Products can also be exposed to what the company calls “dwell time”, the period spent waiting to be loaded or unloaded.
A pallet that might ordinarily spend 37 minutes being unloaded at a particular temperature could face a very different risk profile when the surrounding temperature is 10C or 15C higher, he said.
“These temperature variances and these minor adjustments, they have an impact on the supply chain,” he said. “Every bit of the supply chain has to be recalibrated, from trailer transit all the way through the mechanics of the dwell time and how quickly it moves to refrigeration or freezing.”
From the trailer to the shelf
The issue, according to Khoshniyati, is not simply whether a product has been delivered. It is whether it has remained in the right condition throughout the journey.
The company argues that traditional supply chain tracking can tell a retailer where an item is, but not necessarily what has happened to it along the way.
That distinction becomes particularly important for perishable goods. A carton of meat, for example, could be tracked from a food processor to a shop, while its exposure to temperature changes is monitored at the same time. Wiliot says its system can identify unusual conditions and flag potential problems before a product reaches the consumer.
The technology also uses artificial intelligence to analyse patterns in the data. In the company’s vision, a retailer could ask whether a particular product is safe to use and receive an answer based on what it has experienced throughout its journey.
The executive argues that the same approach could eventually be applied beyond food. Cosmetics, electronics and other goods can also be damaged by prolonged exposure to extreme temperatures, even when the effects are not immediately obvious.
“Condition monitoring is important for every asset out there,” he said.
Khoshniyati compared the problem to the warning that appears on a mobile phone when it becomes too hot. The immediate danger may disappear once the phone cools down, but repeated exposure to high temperatures could still affect its components over time.
The same principle, he argues, applies to products moving through a supply chain. The damage may not always be visible at the point of delivery, but it could affect product quality or shelf life later.
The challenge for retailers is how to introduce such technology without throwing away the systems they already have.
Khoshniyati says it takes an approach of working alongside existing infrastructure, including barcodes, QR codes, RFID and machine vision systems. The company argues that its tags can be used with some existing infrastructure rather than requiring retailers to start again from scratch.
The cost of scaling technology across a supply chain has historically been one of the barriers to more granular monitoring, according to the executive. He said RFID infrastructure, for example, can require significant capital investment when deployed at scale.
The company’s existing work includes Royal Mail, which the executive described as a UK example where Wiliot has worked with existing investments and processes. He also pointed to a nationwide deployment with Walmart in the US, covering more than 4,600 stores, as an example of the technology being scaled.
The executive suggested that broader international expansion could follow, although he did not provide details.
For retailers facing the prospect of more extreme weather, however, the question is whether technology alone can solve the problem.
The answer may instead involve a combination of investment in physical infrastructure and better visibility of what is happening inside it.
Recent events suggest that even the most visible part of the cold chain, the supermarket refrigerator, is already under pressure. More than half of the UK’s 460 cold storage facilities for food and pharmacy are more than 20 years old, with concerns that older buildings and refrigeration systems may struggle during prolonged periods of extreme heat.
That makes the cold chain a broader adaptation challenge. Retailers need to consider not only whether a refrigerator can keep a product cold once it reaches the shop, but whether the infrastructure behind it can withstand a hotter climate.
The Food Standards Agency has warned that higher temperatures can make it harder to maintain safe refrigeration, with food ideally kept between 0C and 5C.
For Khoshniyati, the next step is to make the condition of products as visible as their location.
The company’s longer-term vision is strikingly simple. A customer sitting down to eat a piece of sushi or a steak could, in theory, ask the product itself whether it was safe to eat, based on a record of everything it had experienced before reaching the plate.
“The ultimate vision here is that you go to a sushi restaurant, you go to a steakhouse, you know, seafood, whatever the preference is, and before you eat your item, you can ask your item, ‘Are you safe to eat?’” the executive said.
That may sound futuristic. But the technology behind it is being built around a problem that is already becoming more immediate.
As Britain gets hotter, the cold chain will have to cope with conditions for which much of its existing infrastructure was not designed.
“The future that we’re really marching towards,” Khoshniyati said, is “being able to get that level of interaction with your physical item.”
Ultimately, he said, the technology is not only about brands or logistics. “End of the day, it has to do with the customer.”
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